Geological Summary

Izu Peninsula Geopark is a unique location where an ongoing collision between two

island arcs (Honshu Arc and Izu Bonin Arc or IBA) is visible. The peninsula formed as

a submarine volcanic massif on the Philippine Sea Plate due to Pacific Plate

subduction about 20 Ma (geological evidence), and collided 1 Ma~0.6 Ma. with the

Honshu Arc (located on Eurasian and North American Plates) due to the northward

motion of the Philippine Sea Plate. The whole landmass underwent crustal uplift and

became a peninsula upon ‘collision’. Terrestrial polygenetic volcanism took place after

peninsular landmass formation—and ongoing crustal motion, active faults, and

monogenetic volcanic field activity make Izu a dynamic location. The collision between

IBA and Honshu is actually a part of ‘multiple-collision’ and assimilation of

landmasses, these are important continental crust formation mechanisms. This

geological history is reflected on the natural heritage of the Izu Peninsula.

B. GEOLOGICAL HERITAGE

B-1 Location

Izu Peninsula geopark is located in the east-central part (Pacific coast side) of the Honshu Island in Japan.

Latitudinal and longitudinal extents are: Latitude: 34.6 N and 35.2 N, Longitude: 138.7 E and 139.2 E.

The peninsula, while seemingly an integral part of the Honshu Island, is geologically formed on the northern

tip of the Philippine Sea Plate which subducts beneath the continental plate boundary at the eastern coast of

Japan (most of the island landmass of Honshu is geologically part of the North American and Eurasian

continental plates). The Izu Islands and Ogasawara (Bonin) Volcanic Arc, result of the subduction of the

Pacific Sea Plate below the Philippine Sea Plate, are located to the south of the peninsula. The Izu Peninsula is

also located on the northern limit of the Izu-Bonin Arc (IBA). It is a geologically unique location where the

IBA is colliding with the Honshu Arc. The peninsula is bounded by deep troughs created due to the

subduction of the Philippine Sea Plate under the continental plate margin: Suruga Trough (West) and the

Sagami Trough (East)—which create the two deepest bays of Japan. Within a mere 20 km distance from the

coast, the depression within these troughs falls rapidly to 1500-2500 meters.

The Kuroshio Current, one of the main marine currents that influence the waters around Japan, brings the

influence of warm temperate climate to the area. For this reason, plant and animal species that are more

commonly found in comparatively southern locations are seen in the peninsula. On the other hand, as the

peninsula is geographically an extension of Honshu, plants from the northern locations have also colonized

the area. Due to its location, Izu Peninsula is known as both northern and southern limits of a number of

species habitats. There are a number of endemic species found within the peninsula, most of them have the

words Izu or Amagi (central highland) attached to their names. Due to the convergence of various climatic,

geological and geomorphological factors, the intra-species diversity is also rich. For several plant species,

E139° E140° E138°

N35°

N34°

N33°

Tokyo

Miyakejima Island

Mt.Fuji

Philippine Sea Plate

Pacific Plate

Eurasian Plate

(Amurian plate)

North American Plate

(Okhotsk Plate)

3～6cm/year

8～10cm/year

Geopark area (Terrestrial)

Philippine Sea Plate

Niijima Island

Tanzawa Mountains Akaishi

Mountains

Izu Peninsula

Source : ETOPO2

Izu-Oshima Island

Fig.7. Izu Peninsula’s location at plate margin

flowering times differ compared to their colonies elsewhere in Japan. There are a number of natural species

variants within the area, making the peninsula ecologically rich. The warm temperate climate helps colonies

of ferns and several types of vascular and woody plants to flourish. The highlands near the southern coast are

rich in vegetation types such as Canopy Layer Vegetation, Sub-canopy Layer Vegetation, Understorey

Vegetation and Undergrowth Vegetation (Grassland). In the central Amagi Highland, tall Emergent Layer

Vegetation can be seen, some of the trees here are also hundreds of years old. The northern part of the

peninsula also features rich natural forests in places, such as the old-growth preserved forest in Kannami

Town, as well as special type of small vegetation colonies such as the Juniper colony on the sand-spit of

Osezaki (some trees are nearly a thousand years old).

The two bays of Sagami and Suruga are home to a diverse range of marine species due to the deep troughs

created by subduction process. The rich marine ecosystems provide a rich diversity of fish catch for local

societies, some of the well-known products of this region include the Beryx splendens (Splendid alfonsino,

locally known as Kinmedai). Many tropical and subtropical fish species inhabit or frequent the waters around

the peninsula, notable examples include Chromis notata (Pearl-spot chromis, locally known as Suzumedai),

and Chaetodon auripes (Oriental Butterflyfish or Chocho-uo in Japanese). Most of these fish species are

seasonal visitors, they arrive in flocks with the inflow of the Kuroshio, but they are unable to withstand the

temperature drop in winter. The Uchiura Inlet off Numazu City is also the northern limit of a species of reef-

building coral.

B-2 Geological Description

The main geological characteristics of the Izu Peninsula stem from the fact that a submarine volcanic massif

on the Philippine Sea Plate drifted and collided with Honshu, generating various volcanic and crustal

processes. The main geo-story of the Geopark derives from this geological event: Izu Peninsula is the only

location in the world where an ongoing collision between two island arcs is taking place. The main theme of

the Geopark: ‘Volcano Gifts from the South’—addresses the various landform, landscape, ecosystem and

cultural features of the peninsula that can be attributed to this geological history.

Suzumedai Murehatatatedai Kumanomi Minokasago lionfish

Endemic

Izuasatsuki

Endemic

Amagitsutsuji Isogiku plant Nachishida fern

(northern habitat limit)

The IBA is formed due to the

subduction of the Pacific Plate

beneath the Philippine Sea Plate.

The Philippine Sea Plate moves

towards a northward direction and

itself subducts under the

continental plate margin beneath

the island arc of Honshu. The IBA

moves northward due to the motion

of the Philippine Sea plate, and this

creates the active collision zone

between IBA and Honshu island

arcs. The Izu Peninsula is located

near the northern tip of the IBA, it

is an allochthonous block that

became a part of the continental

crust due to the collision between

two volcanic arcs, as described

above. Prior to Izu Peninsula’s assimilation in the

continental crust that took place more than 1 Ma, the

Tanzawa Massif had collided and been assimilated in

the continental crust about 5-6 Ma. It is postulated that

even older collisions, those of the Misaka and

Kushigatayama Massifs, had taken place. Thus the Izu

Peninsula and its surrounding areas are not only a

location of collision between island arcs due to plate

motion, but it is a region where ‘multilayered’

collision evidences as well as repetition of collision

events, accretion of landmass and continental crust

formation, can all be seen. The region has long been

researched for tectonic processes, formation the

Japanese archipelago, and submarine volcanic

deposition. The Izu Peninsula allows a momentary

glimpse (in geological time-scale) on the ongoing saga

of multiple collisions and crustal evolution processes.

It is a special location where one can sense the

dynamic nature of our planet.

In addition, it must be noted that the multiple

collision events due to the movement of IBA at the plate margin are responsible for a number of geological

peculiarities observed in central Honshu Island such as crustal deformation, rotation and crustal uplift. For

example: the Akaishi Mountain Area (Southern Japan Alps) started to be uplifted from the early Pliocene

Epoch, and this uplift became even more pronounced since 1 Ma, after Izu’s collision with Honshu. The rate

of uplift is calculated as several thousand meters/ Myr and recent rates of 40 cm in 100 years have been

observed. Currently, landforms mainly arising out of volcanic processes dating back 20 Ma have been

confirmed in this area, and two geological periods (the Neogene and the Quaternary Periods) are represented

in the geological history of the Geopark.

Fig.9. Crustal motion of past 100 yrs. in Japan

Fig.8. Geotectonic structure of central Japan (left), collision of

island arcs (right)

Most of the land forms that date back beyond 2 Ma were created out of

submarine volcanic deposition, secondary deposition layers, and

intrusive sheet formation (Dikes). These submarine volcanic landforms

are grouped into the Nishina, Yugashima and Shirahama Groups.

Fossils and paleomagnetic records from these layers clearly prove that

Izu was located in a far lower (comparatively southerly) latitude in the

geologic past. During the period of 2-1 Ma, the submarine volcanic

deposition layers become absent, indicating the period of collision with

Honshu and crustal uplift. The sandstone/mudstone layer that is found in

the central part of the peninsula (lower part of the most geologically

recent Atami Group) records deposition upto 600,000 years ago. This

was the time when the whole of the peninsula became a part of

continental Honshu. The landforms subsequent to this point are products

of terrestrial volcanism. Large scale terrestrial volcanism continued in

Izu Peninsula until about 200,000 years ago, Mount Amagi was among

the main volcanoes that erupted during this period. Polygenetic

volcanism of this period gave rise to large highlands, Mt.

Banzaburodake in Amagi (1405 m asl) is the highest peak in Izu

Peninsula today.

After this phase of polygenetic terrestrial volcanism drew to a close, a

fresh phase of terrestrial volcanism began about 150,000 years ago: this

was the beginning of the monogenetic volcanic phase, represented by

numerous small volcanoes of the Izu Tobu Volcanic Group. This phase

is still active, a moderate submarine phreatomagmatic eruption off the

Ito City coast in July 1989 was the most recent volcanic event. Frequent

earthquake swarms and crustal movements caused by magma intrusion

are observed in this region. The Philippine Sea Plate motion continues

to push Izu Peninsula further into the continental crust, as a result there

are several active faults such as the Tanna and Irozaki Faults.

Fig.10. Izu Peninsula at plate junction

Fig.11. Different periods of Izu Peninsula’s geostory

Fig.12. Geological structure of the Izu Peninsula

B-3 Description of Main Geosites

B-3-i Geosites Conceptualization and Management

In Izu Peninsula Geopark, ‘Geosites’ are conceptualized in a manner where they narrate about a part of the

geostory, the geosites are a combination of points which are mutually related. For this reason, there are one or

multiple ‘Geopoints’ within the same Geosite. Geosites are in turn combined to form ‘Areas’ which are the

biggest collective units of geological heritage in the Geopark. The Areas are conceptualized by keeping in

mind the range of visitor movement and management related logistics. Areas are also naturally divided among

watersheds and other types of geomorphological boundaries: there are a total of 11 areas in the geopark.

Izu Peninsula Geopark has 313 Geopoints in 114 Geosites. Geopoints also involve locations where it is not

possible for common visitors to access the site due to safety concern or specially restricted sites. While it is

not sometimes possible to utilize such sites for geotourism, many among these have particular geoscientific

and research purpose value, hence they are inscribed in the Geopoint list. Thus, the Geopark manages

Geopoints based on the ‘Use/Value Type’. A list of geopoints along these divisions are given below.

Table 4. Geopoint categories and details

Geopoint Type Details Number

General access

These sites can be visited by anyone: tourists, residents or researchers.

They pose no or little difficulty of access, visitors can get a sense of the

geostory of the peninsula. Website or pamphlet based guidance is

available, explanation panels are also present in many of these sites.

159

Limited access

These sites can be visited by anyone: tourists, residents or researchers. But

some of them pose difficulty of access or some safety concern. These are

also valued for their common geotourism purpose. Visitors can access

these sites when geoguides or tour operators are present.

27

Education

purpose

These sites have particular value for geoscience researchers. They pose no

or little access issues, but sometimes the contents/explanation are not

easily explained to all levels of visitors. Based on demand, information

about these can be provided by the geopark, and is inscribed in the

geospoint manual.

105

Research purpose

Mainly for research purpose. They have geoscientific value but most are

accessed with considerable difficulty. The geopark provides special

guidance about these sites on a case-by-case basis.

22

Total 313

Geographical Information System

(GIS) database is used to manage this

large number of sites. This database is

not available for the general public,

but the geopark provides relevant data

to engineering or construction

projects approved by administrative

authorities. The geopark also provides

training for construction workers to

prevent damage to the sites.

Fig.13. Geosite/ geopoint database

B-3-ii Description of Main Geosites

A detailed list of all geosites is available at the end of the application, and as an Appendix.

Here some key geosites and their significances are discussed.

The main Theme of our geopark reads: Volcano Gifts from the South. This overall theme describes the

formation and geological structure of the Izu Peninsula, it is in turn subdivided in to 5 themes depending on

geological periods and cultural facets of the geohistory.

1. A southern volcanic massif drifted in and collided with Honshu

2. Izu’s submarine volcanic roots

3. Formation of the peninsula and terrestrial volcanism

4. A ‘living’ peninsula

5. Dynamic local knowledge and culture related with geological change

1. A southern volcanic massif drifted in and collided with Honshu: Different types of collision

evidence

The main geological characteristic of the Izu

Peninsula is that it did not originally form

inside the Japanese archipelago, but is the

result of a collection of submarine volcanoes

in the south sea that gradually came closer to

the Japanese landmass with Philippine Sea

Plate movement and eventually collided with

Honshu Island. Two important indirect and

direct proofs of this geologic past are

paleomagnetic records and fossils in the

rocks. The study of paleomagnetism in the

rocks has proven that Izu was originally

located in a far southerly location: a chart of

the paleomagnetic property is given on the chart at the right. But this evidence is only understood by

researchers and cannot be readily ‘seen’. Fossils in the rocks of Izu are easier to understand as they can be

seen or felt directly. Limestone or Calcareous Sandstone found in the Shimoshiraiwa (Izu City at the central

part of the peninsula), Shirahama (Shimoda City in the south) and Nashimoto (Kawazu Town along the east

coast) are typical locations of marine fossils.

Geosite Name: Shimoshiraiwa Kadono Area: Nakaizu

Subtheme: A volcanic massif drifted in from the south and

collided with Honshu

Type: General Access

Geopoint Name: Shimoshiraiwa

Calcareous sandstone at Shimoshiraiwa

Fossils of marine organisms from inside the cliff are direct

evidence of Izu’s former southerly origin. The Calcareous

Sandstone cliff in Shimoshiraiwa, tilted at a 30～40°angle, yields

fossils of Lepidocyclina foraminifera, small corals, sea urchin and

shells dating 11 Ma. These fossils are found in Izu only, the rest

of the mainland Honshu was influenced by a cold climate at that

time. These fossils thus are direct proofs that 11 Ma when Japan

was located in a cold climatic zone, Izu was located in a warmer

southern marine environment.

Fig.14. paleomagnetic records

The Lepidocyclina foraminifera fossils are a Shizuoka Prefecture

designated natural property. Fossils upto 5 mm diameter are

found from the cliff, these are relatively large for foraminifera

size, and are easily observed with the naked eye. Shimoshiraiwa

is an important geosite to learn about plate tectonics and land

formation.

Fossils from the sandstone cliff

In addition the ‘Last Sea’ that formed due to the collision between the volcanic massif and mainland Honshu,

deepened due to plate subduction at the continental margin and gradually became a separated body of water

and was eventually filled up by deposition layers—is a geologically important phenomenon. Mud and gravel

layer from this sea accumulated at locations like Jo and Ikada-ba in Izu city. Most of the peninsula is volcanic

in origin, so this type of distinctive sedimentary deposition layer is quite rare in Izu.

Geosite name: Yokoyama Umegi Area: Nakaizu Kita

Subtheme: A volcanic massif drifted in from the south and

collided with Honshu

Type: Research oriented

In the Yokoyama Umegi Geosite, the mudstone/gravel layer that

was deposited under the ‘Last sea’ can be observed and the gradual

filling up of this water body can be inferred. 1.2 Myr fossils of

organisms that were living in the old seabed are found in these

deposition layers. This type of sedimentary deposit is rare in Izu:

where most of the land was created due to volcanism or volcanic

fallout. This is also the final landform that had a marine origin in

Izu. All subsequent layers are products of terrestrial volcanism.

This indicates that about 1 Ma, Izu became an integral part of

Honshu and the final stretch of water body located between them

filled up.

Silt layer of Yokoyama

2. Izu’s submarine volcanic roots: Submarine volcanic deposits and volcanic necks

Most of Izu was a submerged volcanic massif before of 2 Ma. Submarine volcanic products can be seen in the

dynamic and beautiful coastline of Izu that is a product of crustal uplift and terrestrialization of submarine

volcanic deposits. These strata form the bedrock of the peninsula at various stages: they are grouped into

Nishina, Yugashima and Shirahama Strata Groups (oldest to youngest in geologic age).

The oldest of these strata, the Nishina Group, is found in the middle to downstream parts of the Nishina River

in the western part of the peninsula. The main component of this layer is early Miocene volcaniclastic deposits,

which take the form of subaqueous lava and subaqueous debris flow. Basaltic pillow lava indicating underwater

eruption is also found within this strata.

Geosite Name: Nishina Hozoin Area: Nishiizu

Subtheme: Izu’s submarine volcanic roots Type: General access

Geopoint Name: Ishiki

Pillow lava of Ishiki

The Ishiki area in Nishi Izu Town has an outcrop of basaltic pillow

lava belonging to the Nishina Group. This is a very important geosite

as it enables us to know about the submarine rots of the peninsula. The

pillow lava here is composed of 30~80 cm tubes of aphyric basalt of

pale ash-green color. Minerals like Chlorites fill in the gaps in the

basaltic tubes to form an amygdaloidal structure. Such mineral fillings

give a distinct coloration and pattern to the rock, and fragments are

often used in the bathtubs of hot spring resorts or washing areas. Dikes

that cut across pillow lava layers are also observed in this area.

The Yugashima Group strata are found mainly along the valleys that radiate across the central part of the Izu

Peninsula. Volcaniclastic products from early to mid-Miocene are common and deep marine deposition forms

such as Turbidites are seen. Many of such deposits have subsequently undergone hydrothermal weathering.

Many hydrothermal ore deposits were previously mined at locations like Toi, Seigoshi, Mochikoshi, and

Nawaji.

Geosite Name：Hinata Area: Nakaizu Kita

Subtheme：Izu’s submarine volcanic roots Type: Research oriented

Geopoint：Turbidite of Kajiyama

Turbidite outcrop at the right bank of Kanogawa

Very good examples of Turbidite outcrops are seen in

the lowland areas in along the Kanogawa and Omigawa

Rivers. These belong to the Yugashima Group. A

prominent turbidite outcrop is seen on the other side of

the Kanogawa bank at Izu City. The bedding pattern is

clear due to differential erosion of different particle

sizes, and one can confirm the graded bedding pattern in

the outcrop.

The Shirahama Group Strata is common in Izu Peninsula. It forms the ‘bedrock’ of the peninsula. This strata

is volcaniclastic deposition formed on the older Yugashima layer in the late Miocene and early Pliocene. Its

origin is similar to the Yugashima layer but the Tuffaceous sandstone with cross lamina patterns yield fossils

of shallow marine environment, proving that the layer accumulated in a shallow marine stage of land

formation. This indicates that along with the progress of the collision between the Izu massif and the

continental Honshu, the intermediary water body had shrunk and become shallow. This layer forms many of

the beautiful and varied landscapes in the coastline, crafted through wave action and erosion.

Geosite name: Dogashima, Nishina Port Area: Nishiizu

Subtheme：Izu’s submarine volcanic roots Type: General Access

The surroundings of the Dogashima Area in Nishiizuis a location

where subaqueous debris flow remnants, volcanic ash and pumice

layers that accumulated on top of the flow, and hyaloclastic lava

are seen along the coast. This is a major research site for

exploring submarine volcanism as one can see different stages of

submarine volcanic activities.

Beautiful tuff cliff with cross lamina

Tuff deposition on subaqueous

volcaniclastic flow

Geopoint name：Dogashima Coast South

In the southern part of the Dogashima Coast, tuff cliffs with cross

lamina patterns, and gradually flowing layers of subaqueous

debris flow located underneath can be seen. The submarine debris

flow shows an overall graded structure, staged thermal

demagnetization experiments on the gravel inside the debris flow

indicates a temperature of 450～500°at formation. The top part

of the subaqueous debris flow meshes with the cross lamina,

indicating the possibility that the two depositions were related.

Volcanic bombs with chilled margin are lodged within these

deposits, offering a glimpse at the intense submarine volcanism

that gave birth to these products. The coast of Nishiizu is also a

famous tourist area.

In addition many sea caves were later created through wave

action in these deposits. Boat ride from Dogashima allows

visitors to enter such caves, a particularly large sea cave with an

open top (known as ‘Tenso-do’ or open top cave) is particularly

popular.

In the Yugashima and Shirahama layers, many volcanic necks and magmatic dikes are seen. These were

revealed through erosion after Izu became a part of the continental Honshu. Some of the low rising mountains

are actually volcanic necks, with fascinating examples of columnar joints.

Geosite Name：Iwachi, Ishibu, Kumomi Area: Nishi Izu

Subtheme：Izu’s submarine volcanic roots Type: General access

Geopoint name: Senganmon

Senganmon

The southern part of the southwest coast of Izu Peninsula is a

nationally famous tourist area, it has numerous locations where

intrusive rock formations add variety to the coastline. Senganmon is

one of these intrusive formations. Later a sea cave opened up due to

erosion, creating a gate-like structure. The Japanese word Senganmon

can be roughly translated as ‘Priceless Gate’. The rock mass shows

intricate columnar jointing, indicating that it was a passage of magma

flow in the past. It is possible to cruise right up to the Senganmon

either from Dogashima or from Matsuzaki cruise line. Senganmon is

also a famous sunset point.

3. Formation of the peninsula and terrestrial

volcanism: Terrestrial Volcanoes and the

Backbone of Izu Peninsula

Large terrestrial volcanoes like the Amagi and

Daruma began activity after the collision between the

Izu massif and Honshu and after Izu became a

peninsula. It is estimated that these polygenetic

volcanoes once rose up to 2000 m. These large

volcanoes stopped activity about 200,000 years ago,

and subsequent erosion has reduced their size. Their

summit cones collapsed due to erosion, so today

identification of the crater in many of these

volcanoes difficult. However, as one looks at the long ridge that runs along the Izu Skyline, and the highland

that stretches from Amagi through Nekko-dake to Darumayama—one is able to get a sense of the once majestic

mountain chain that forms the spine of the peninsula today.

Geosite Name：Uomizaki Area: Atami

Subtheme: Formation of the peninsula and terrestrial volcanism Type: General Access

Geopoint name: Nishiki-ga-Ura

Nishiki ga Ura

Hotels stand on the cliffs at Uomizaki

The deeply serrated coast of Uomizaki is actually a part of the

eroded Taga Volcano (active 800,000 to 300,000 years ago). One

can see the initial stage of the Taga volcanism in this area.

Because breccia from phreatomagmatic eruption is present, the

site yields the important insight that the Taga volcano began its

activity during the shallow marine stage of the evolution of the

peninsula.

These days, hotels and resorts have been developed in the area,

some of these facilities are located directly on the precipitous

cliffs. These hotels and resorts allow visitors to get a first-hand

experience of volcanic deposits and the steep terrain. Some wave

cut platforms are used as open air spring baths (Roten-buro):

these are great example of local societies and tourist facilities

harmonizing with the geological heritage.

The gently sloped mountain valleys and foothill areas created during this terrestrial volcanic phase are used as

tourist spots, orchards, pasture-land in the Nakaizu and Kitaizu (in the center and north of the peninsula)

areas. These volcanoes are also the highest elevation points in the peninsula which attract rainclouds.

Fig.15. the ‘spine’ of izu

4. A ‘living’ peninsula:

Although Izu is now assimilated into the continental plate

landmass of Honshu and the activity of large terrestrial

volcanoes stopped long ago, the event of the ‘collision’ is

not over yet. The motion of the Philippine Sea Plate at the

continental plate margin continues to push Izu further into

the continental crust. In addition as the peninsula is

located near the Pacific Plate subduction margin, active

volcanism continues.

Izu Tobu Volcanic Group: Small-scale volcanism

creating diverse landforms

About 150,000 years ago, a distinct new form of

volcanism began in Izu Peninsula. The Izu Tobu Volcanic

Group (literally East Izu Volcanic Group) is a collection of

relatively small monogenetic volcanoes spread on the

peninsula from central to eastern parts and in the

submarine area between Izu and Izu Oshima Island. A group of monogenetic volcanoes is a rare occurrence in

the Japanese archipelago, where most volcanoes are created due to compressive stress field mechanism: apart

from Izu Tobu, the Abu Group in Yamaguchi Prefecture and the Fukue Group in Nagasaki Prefecture are the

only examples of active monogenetic volcanic fields. In Izu, this type of volcanoes creates diverse landforms

such as scoria cones, maars and lava domes. Lava from these volcanoes flowed into the sea or into steep

gorges and created, flat plateaus or plains in the peninsula. These newest phase of volcanism has resulted in

diverse and beautiful landscapes in the peninsula.

Geosite Name: Omuroyama Area: Ito

Subtheme: A Living Peninsula Type: General Access

Geopoint name: Omuroyama

Omuroyama Scoria Cone

Panorama from Omuroyama Summit

The Omuroyama Scoria Cone is the largest scoria cone of the Izu

Tobu Volcanic Group, it was created in a 4000 year old eruption.

From the summit, one can see a panorama of the many volcanoes in

Ito Area and the land created by this type of volcanism: it provides

a vantage point to see the small monogenetic volcanoes.

A large amount of lava issued from the volcano during its eruptive

phase and filled out the jagged area near the sea shore—this is

known as the Jogasaki Plateau today. The lava flow that reached

the Sagami bay created a beautifully varied coast at Jogasaki. The

lava was mostly spewed out from the flank of this cone. A lava

dome formed at the crater during the last stage of the eruption as

the lava became increasingly viscous. The Omuroyama Scoria

Cone is protected as a national natural monument, and we can

enjoy the beautiful shape of the cone due to the long practice of

yearly vegetation burning.

Fig.16. Izu Tobu Volcanic Group

Geosite Name: Kawazu Nanadaru (Seven Waterfalls of Kawazu) Area: Kawazu/Higasiizu

Subtheme: A Living Peninsula Type: General access

The lava from the Izu Tobu Volcanic Group created many a scenic

waterfall across Izu. The Seven Waterfalls of Kawazu are one among

these. About 25000 years ago, a volcano called Noborio-minami

erupted at the southwestern section of the Amagi area. The lava from

this eruption flowed for about 2 km along the Kawazu River valley,

blocking the Kawazu gorge. Water flowing subsequently on the layer

cascade through the elevations created by the lava, creating the 7

waterfalls. These are the Kamadaru, Ebidaru, Hebidaru, Shokeidaru,

Kanidaru, Deaidaru, and Odaru, from upstream to downstream.

Columnar joints are visible in nearly all of the falls. Different angles

of columnar jointing are exposed at different locations, creating a

dynamic scene. This area was the backdrop of the famous novel ‘The

Dancing Girl of Izu’ by Yasunari Kawabata and the Odoriko

(Dancing Girl) Trail is popular among hikers.

Other notable waterfalls created due to the lava flows from the Izu

Tobu Volcanic Group are Joren Waterfalls and Namesawa Gorge

Rapids—many of them are also backdrops of famous literary works.

Kamadaru waterfall

The Changing Face of the Earth due to Crustal Motion and Fault Movement

Izu continues its momentum of pushing into the Honshu Island today, and as a result the land is pushed in

northwest direction, causing landform changes in this region of Honshu. Active faults are the most readily

recognizable forms of crustal motion. A number of active faults are located in Izu, the Tanna and Irozaki

Faults are probably the most famous of these. Together they give a sense of the changing face of our planet.

Geosite Name: Tanna Basin Area: Kannami

Subtheme: A Living Peninsula Type: General access

Geopoint name: Tanna Fault Park

A part of the Tanna fault

Lateral movement at Tanna fault park

On 26 Nov 1930, a large earthquake rattled the northern part of the

peninsula. This is the Kitaizu earthquake (Magnitude 7.3). This

large earthquake caused lateral movements in the Tanna and

Himenoyu Faults (Himenoyu is located southeast of Tanna). The

movement was by as much as 2m. One can see the lateral

movement of the fault by visiting the Tanna Fault park, the

displaced section is preserved as a national natural monument. It is

thought that the Tanna Fault moved by 1 km horizontally and by as

much as 100 m vertically from the location where it was first

created. Tanna Fault was a subject of intense geological research on

lateral fault movement and some of the pioneering lateral fault

research in the world took place here. In this sense the Tanna Fault

has a global level geological significance. The lateral movement of

the fault during the Kitaizu quake directly affected the construction

of the Tanna Tunnel. Due to the tunnel construction, groundwater

(springwater) from the Tanna area was affected and horseradish

(wasabi) farming took a hard hit. Compensation from the railway

construction project was used to turn the area into a dairy farming

hub.

Tanna

Fault

Park

5. Dynamic local knowledge and culture related with geological change

The local society is the core of the 5th subtheme: how people of the

peninsula related to and utilized parts of this geological heritage.

Use of land features, volcanic ejecta, ore deposits,

geothermal energy and water

Izu Peninsula is a place where a volcanic massif (Izu massif) moved

into Honshu with the motion of the Philippine sea plate, collided at

the continental plate boundary and eventually became integrally

attached to the continental crust. Crustal motion and earthquakes are

still observed in this geologically dynamic peninsula. Izu is a land of

steep mountains and jagged coastlines. The erosion processes have

not yet taken a major toll on the volcanic rocks, which are regularly

found on the thin topsoil layer. Unique vegetation characteristics are

observed here due to these land features, warm climate and lots of

rainfall.

The groundwater that enters the soil layers come out as ‘springs’ due

to the fissures in the lava layers in many places. A part of the

groundwater is geothermally heated and comes out as ‘hot spring’

(onsen in Japanese). Some farming products use this geothermally

heated spring water. Hot springs and geothermal heat also contribute

to accumulation of hydrothermal ore reserves. Many such reserves,

notably gold reserves—were mined in the past.

Thus many of the geological characteristics of the peninsula also

formed integral parts of the local life. Though the general

topography is jagged, newer lava flows filled in gorges and steep

terrains to create relatively flat land: these areas were later used for

living, farming and grazing animals, they are also developed into

golf courses and resorts recently. Furthermore, the beautiful

landscape and rock patterns visible in the coastline and cliffs are

major tourist capitals.

Fig.17. Major goldmines in Izu

Hot spring melon farming

Geosite Name: Mishima Area: Numazu Mishima

Subtheme: Dynamic local knowledge and culture related with

geological change

Type: General Access

Geopoint Name: ：Komoike Pond, Shirataki Park

Water issuing forth from fissures

in the lava at Shirataki Park

Mishima City is located in the northernmost area of the peninsula, this

is also a location of the Kisegawa River alluvial fan deposit (Kisegawa

flows southward from the eastern flank of Mt. Fuji). Tagata Plain—the

only large plain in Izu—is created by the Kisegawa deposition.

Lava from a major eruption of Mt. Fuji about 10000 years ago is

widely distributed over Mishima City. This lava is called Mishima

Lava. The porous Mishima Lava layer is directly attached to the many

springs that issue forth in the city and behind the flow of many small

rivers. This water-landscape provides a unique atmosphere to the city,

and is deeply related to the local culture. The Mishima Eel, a famous

local delicacy, is highly rated for its lack of exces fat and smell,

properties that can be attributed to the springwater of Mishima.

A number of igneous rocks were used as attractive ‘stones’ in the past, still one can see many old stone

quarries in the peninsula.

Geosite Name: Iwachi, Ishibu, Kumomi Area: Nishiizu

Subtheme: Dynamic local knowledge and culture related with

geological change

Category: General Access

Geopoint name: Muroiwado

Quarrying marks are left on the mine

walls, volcanic bombs can be seen

lodged in the Tuff.

From olden times the ‘Izu Stone’ or stones quarried from the

peninsula were prized as construction material. There are 2types

of ‘Izu Stone’: a ‘hard’ form that is mostly terrestrial volcanic

ejecta and intrusive dike parts and a ‘soft’ variety which is

actually older, tuff formation as represented in the Shirahama

layer. The Muroiwado abandoned quarry was used till the end of

the Edo Period (1603-1868). Stone quarried at this location was

used in as far away as Shinagawa in Tokyo, where the Odaiba

Battery Ground was constructed with this type of stone. Quarries

where this ‘soft’ stone was cut and processed are found all over

Izu; but Muroiwado is the only location where visitors can access

the full site.

Advanced Disaster Prevention and Disaster Reduction Measures

The geological characteristics of the peninsula sometimes cause natural disasters. For example: the steep

terrain and heavy rainfall cause frequent flooding and landslides. Among the recent large scale disaster events,

the 1958 Kanogawa Typhoon can be cited. This extreme rainfall and flooding caused widespread damage in

the central and northern parts of Izu. Plate dynamics and fault movements cause large earthquakes throughout

the peninsula. Two recent examples are the Kitaizu earthquake (caused by the Tanna Fault) in 1930 and the

Izu-hanto Oki earthquake in 1974 (caused by the Irozaki Fault). There are two deep troughs off the coasts of

Izu caused by plate subduction: the Suruga and Sagami Troughs—these had time and again caused

catastrophic earthquakes known as Tokai and Kanto Earthquakes respectively. The earthquakes caused violent

shakings and tsunami waves that devastated the region in the past. In addition frequent volcanic eruptions in

and around Izu is continuing. The submarine eruption off the Ito coast in 1989 is a recent example. This was a

modest eruption, but the event had a far-ranging effect on the society. The magma that caused this eruption is

still active, causing earthquake swarms time to time.

One of the main characteristics of the geopark is the presence of disaster reduction and disaster prevention

programs. Izu Peninsula Geopark has a number of tsunami and flood prevention structures, and many geosites

provide lessons of past natural disasters. Together, these provide us the opportunity to understand about the

local knowledge used to prevent natural disasters, even while enjoying the beautiful panorama presented by

the dynamic earth.

Geosite Name: Izu Nagaoka Area: Nakaizu Kita

Subtheme: Dynamic local knowledge and culture related with

geological change

Type: General Access

Geopoint name: Mamanoue

The mouth of the drainage canal

The Kanogawa River receives a lot of silt and debris from the

quaternary volcanoes of Izu, as well as debri from Mt. Fuji and

Hakone. This causes frequent flooding and landslides that affect the

Tagata Plain. The Kanogawa Drainage Canal is the result of a 14 year

long project to divert the flood wave from the narrow lower part of the

watershed directly to the sea. The drainage canal can bypass a peak

flow of 2000 m3/s. A document repository of the Ministry of Land,

Infrastructure, Transport and Tourism (MLIT) is located at this site, it

provides opportunity to learn about the nature of Kanogawa River and

its history of flooding.

Nature and Local Beliefs

The natural disasters of the past also left an indelible mark on the culture and beliefs of the local society. The

chief deity of Izu, Oyamatsumi or Mishima Daimyojin (worshipped at Mishima Shrine, the most important

Shinto Shrine in Izu)—is a god with a volcanic connection. Thus, whenever there was an eruption, the deity

was seen as important. There are a number of shrines along the coast that worship the gods and goddesses of

the Izu Islands (group of volcanic islands located east and south east of Izu). Though more research is required

to fully understand the spread of this kind of religious belief, it is thought that the deities were installed in

order to pacify the fiery nature in the Izu Islands. Such beliefs show that the local society, while reaping the

benefits of dynamic nature, also had a sense of awe for the natural forces.

In addition to the fiery deities, there are numerous deities that protect the locals on marine voyages and look

after fishermen. This kind of belief arose due to Izu’s position as a gateway to the seas and the local

connection with the marine world. There are many historic ruins, shrines, and stone engravings, especially in

areas adjacent to ports and capes,--which testify about this unique local culture.

Geosite Name: Shirahama Area: Shimoda

Subtheme: Dynamic local knowledge and culture related with

geological change

Type: General Access

Geopoint name: Shirahama Shrine

The Shirahama Shrine gate facing

Miyakejima Island

The Shirahama Shrine in the Shimoda City in south Izu has a peculiar

feature: a shrine gate (torii) stands facing the Miyakejima Island over

the sea in the backyard. It is thought that this gate was erected to

commemorate the arrival of Goddess Ikonahime in the Shirahama

Shrine. Ikonahime is a goddess of the volcanic Miyakejima. Every

year, a large festival to mark this event is held at the shrine in October,

a key feature is the fire-festival or the Hitachi-matsuri that makes

offerings to the deities of the Izu Islands.

B-4 International, National and Local Importance of the Geosites

One of the important stories of Izu Peninsula Geopark is the collision between a submarine volcanic island

and Honshu. Such collision events are known to have occurred elsewhere, but all other cases date much

farther back in geologic time. If the geologic time boundary is narrowed to 15 Ma when the Sea of Japan

formed, only two events of such ‘collision’ are left: the collision of Tanzawa massif and Honshu about 6 Ma

ago and the collision of Izu. Collision between volcanic island masses is thought to be an important process of

evolution of the continental crust. Izu peninsula is the only location of its kind in the world, where a currently

ongoing process of collision between two island arcs can be observed: for this reason the region is well

represented in international geological research. It is also an internationally well-known region for plate

movement and associated processes.

There are a number of geoparks within Japan that explore volcanism as themes. If the definition of an active

volcano is determined according to the Japan Meteorological Agency standard (volcanoes which are either

active now or have been active within the past 10000 years)—then the following geoparks feature active

volcanoes: Toya-Usu Global Geopark (Mt. Usu), Itoigawa Global Geopark (Yakeyama), Mt. Unzen Global

Geopark (Mt. Unzen), Aso Global Geopark (Aso), Bandaisan Geopark (Bandaisan), Hakone Geopark

(Hakone), Izu Oshima Geopark (Izu Oshima), Hakusan Tedorigawa geopark (Mt. Hakusan), Kirishima

Geopark (Kirishima), Sakurajima-Kinkowan Geopark (Mt. Sakurajima). There are many geoparks where

quaternary and tertiary volcanoes (non-active) are featured.

The Izu Peninsula Geopark explores tertiary submarine volcanism, quaternary terrestrial (polygenetic)

volcanism and the recent, ongoing monogenetic volcanism (Izu Tobu Volcanic Group). This is a diverse range

of volcanic activity, spread over multiple geologic eras. Old volcanic landforms such as volcanic necks and

dikes and submarine deposition, as well as new, diverse topography due to lava flow—can all be seen on the

peninsula. Visitors can see a range of submarine volcanic deposition, terrestrial volcanic deposition and land

formation patterns, and can learn about the movement of plates and land formation events. At this geopark,

visitors are not only acquainted with volcanoes, but as the themes are related to larger geological processes

like plate movement, they can learn about the planetary dynamics and enjoy related land features.

As noted earlier, the Izu Tobu Volcanic Group is a rare occurrence of an active independent monogenetic

volcanic field in Japan. This makes Izu Peninsula the only geopark in Japan which features an active

monogenetic volcano field. The Vulkaneifel Global Geopark in Germany is a prominent international geopark

that features a monogenetic volcano field.

In addition, there are a number of crustal motion events on the peniunsula, such as active fault movement. In

this sense, Izu Peninsula is a unique geopark where one can get an understanding of both volcanism and

crustal motion as parts of the larger set of dynamics involving tectonic motion of plates. This interrelationship

between phenomena and geostories allow the visitor to grasp the mechanisms of our dynamic planet.

Re-evaluation of the natural landform and landscapes through both globally and locally valuable geosites is

also a novel experience for local societies. For locals, the usual utilization of an attractive landscape was as a

tourist resource, so the geopark helps locals cultivate a new set of values about the heritage of their place, by

connecting land features with culture, history and beliefs, and also by reflecting upon the wisdom of co-

existing with natural disasters

Geosite/Geopoint Map

Area Geosite Geopoint Category Details

Ajiro Tateiwa Coast Limited access Dike and magma sputter

Atami Atami General access Landscape of hot spring town

Atami Tanna Tunnel General access Tanna tunnel and dev elopment at Atami

Cape Uomizaki Nishikigaura Coast General access Early phase submarine v ilcanic deposit f rom Taga v olcano

Hatsushima Island Hatsushima Island General access Terraced terrain and uplif t

Izusan Hashiriy u Spa General access Hot spring

Cape Shiof ukizaki, Kawana Eky oin Temple Education purpose Tsunami relief stone

Cape Shiof ukizaki, Kawana Kaizoji Temple Education purpose Tsunami run-up height marker stone

Cape Shiof ukizaki, Kawana South Cape Shiof ukizaki Limited access Sea cav es, crustal uplif t releif , wav e cut bench, v olcanic neck

and dike

Futo Coast, North Jogasaki Coast Cape Kadowakizaki General access Cross section of Omuroy ama lav a, Jogasaki coast

Futo Coast, North Jogasaki Coast North Futo corst General access Omuroy ama lav a f low and columnar joints

Futo Coast, North Jogasaki Coast South Futo Limited access Old eroded clif f lodged in Omuroy ama lav a f low, stone quarry

remnant

Futo Coast, North Jogasaki Coast South Futo General access Old eroded clif f lodged in Omuroy ama lav a f low, top lay er of

lav a f low

Futo Coast, North Jogasaki Coast Une General access Omuroy ama lav a f low and columnar joints

Hachigakubo Volcano, Ogawasawa Babanotaira Volcano Education purpose Babanodaira scoria cone and cross section relief , v iew towards

Izu Kogen highland

Hachigakubo Volcano, Ogawasawa Hachigakubo Volcano Education purpose Hachigakubo crater and ejecta, v iew towards Izu Kogen

highland

Hachigakubo Volcano, Ogawasawa Ogawasawa Riv er Education purpose Hachigakubo eruption induced Kasekiko lake collapse and

legend of the red bull

Hachigakubo Volcano, Ogawasawa Suidoy ama waterspring Research purpose Dikes and water springs, Hachigakubo scoria cone

Ike Ike community center General access Water drainage tunnel and Ike area history , Omuroy ama lav a

f low

Ike Sanjinja Shrine General access Landscape and history of Ike area, lav a domes of Yahazu

y ama, Ananoy ama and Dainoy ama

Ioy ama Volcano, Akakubo Volcano Akazawa Port Education purpose Ioy ama lav a f low and cross section relief

Ioy ama Volcano, Akakubo Volcano Cape Nakanosaki Education purpose Ioy ama lav a f low and cross section relief

Ioy ama Volcano, Akakubo Volcano Ioy ama Volcano Education purpose Ioy ama scoria cone and panorama f rom summit

Ioy ama Volcano, Akakubo Volcano Kouy oudai v illa Education purpose Akakubo tuf f ring landscape

Ioy ama Volcano, Akakubo Volcano South Yawatano Port General access Ioy ama lav a f low and cross section relief

Ito Spa Butsugenji Temple Education purpose Tsunami relief stone

Ito Spa Matsukawa Riv er General access Ito onsen town landscape

Ito Spa Monomigaoka Hill Education purpose Uchino v olcano landscape, ejecta and hot springs

Ito Spa Old air‐ raid shelter of Daitokan Limited access Hachigakubo Babadaira scoria

Joboshi Akasaka Education purpose Joboshi lav a

Joboshi South Akasaka Education purpose Akasaka Minami Maar and related ejecta

Joboshi Sports ground f or Citizen of Ito

city

Education purpose Joboshi crater

Komuroy ama Volcano Komuroy ama Park General access Komuroy ama scoria landscape, Komuroy ama

Komuroy ama Volcano Komuroy ama Volcano General access Komuroy ama scoria hill, Izu Kogen highland panorama

Lake Ippekiko, Umenokidaira

Volcano

Ippekiko Parking General access Ippekiko and Numaike maars, ejecta and lav a f low in to

Numaike

Lake Ippekiko, Umenokidaira

Volcano

Ippekikojinja Shrine General access Ippekiko maar, Omuroy ama lav a f low and Junirento islets

Lake Ippekiko, Umenokidaira

Volcano

Umenokidaira Volcano Education purpose Umenokidaira, Chikubo v olcano ejecta and landscape

Okuno, Kadono Jonohira Education purpose Lav a f rom Kadono and Omuroy ama v olcanoes

Okuno, Kadono Kadono Education purpose Lav a plateau of kadono and Ogi v olcanoes

Okuno, Kadono Okuno Dam General access Dam and society , surrounding landscape

Okuno, Kadono Upstream of Okuno Dam Research purpose Submarine v olcanic ejecta

Omuroy ama Volcano Mt. Iwamuroy ama General access Omuroy ama scoria cone, Iwamuroy ama lav a dome &

landscape, v iew f rom summit

Omuroy ama Volcano Near Ito wax museum Limited access Omuroy ama scoria lay er, ev idence of simultaneous

v olcanism at Hakone and Ippekiko

Omuroy ama Volcano Near Omuroy ama Parking Education purpose Volcanic ash f rom Kozu shima v olcano AD 838

Omuroy ama Volcano Oakland Villa Limited access Omuroy ama scoria lay er

Omuroy ama Volcano Omuroy ama Volcano General access Omuroy ama scoria cone, v iew f rom summit

Omuroy ama Volcano Sakura no Sato General access Open top of lav a tunnel, cross section of lav a f low and scoria

raf t

South Jogasaki Coast Hashidate General access Cross section of Omuroy ama lav a f low, columanr joints and

Jogaski coast panorama

South Jogasaki Coast Igaigane General access Top lay er structure and cross section of Omuroy ama lav a

f low and Jogasaki coast landscape

South Jogasaki Coast Kannonhama Limited access Pothole in Omuroy ama lav a f low and round stone inside

South Jogasaki Coast North Yawatano Port General access Omuroy ama lav a f low landscape and cross section

Teishi Sea-Knoll Teishi Sea-Knoll Limited access 1989 v olcanism remnant and ongoing v olcanism

Usami, Oishigasawa Cape Osaki Research purpose Lav a f rom Usami Volcano

Usami, Oishigasawa Gy orenji Temple General access Tsunami relief stone

Usami, Oishigasawa Oishigasawa General access Stone quarry ruin

Yahazuy ama Volcano Ananoy ama Volcano Education purpose Ananoy ama lav a dome and landscape

Yahazuy ama Volcano Yahazuy ama Volcano Education purpose Yahazu y ama lav a dome, landscape and rocks, use of

springwater

Gekko Astronomical Observ atory Gekko Astronomical Observ atory General access Astronomical observ atory , Fuji Hakone Ashitaka mountains

Ikenoy amatoge Pass Ikenoy amatoge Pass General access Fault v alley landscape

Jikkokutoge Pass Jikkokutoge v iewing spot General access Tanna f ault, Tanna Tashiro basin landscape, Fuji Hakone

Ashitaka and Amagi mountains

Karuizawa Karuizawa Education purpose f ault v alley and stream capture landscape

Atami Area

Ito Area

Kannami Area

Geosite/Geopoint List

Kashiy a Kashiy a ancient grav es General access Py rocalstic deposition of hakone and tunnel tombs in the lay er

Mt.Kurotake Nishitanna Parking General access Tanna f ault, Tanna Tashiro basin landscape, Fuji Hakone

Tanna Basin Oratche General access Tanna landscape, transition to dairy f arming af ter Tanna tunnel

Tanna Basin Tanna Fault Park General access lateral slip during Kitaizu earthquake, underground preserv ation

of f ault structure, Tanna f ault model

Tashiro Basin Karaijinja Shrine General access Kitaizu earthquake f ault slip, Tashiro basin landscape

Amagitoge Pass Kanten bus road Research purpose Kanten f orest road v olacno lav a and lahar f low

Atagawa, Hokkawa Anagiri coast trail General access Amagi v olcano lav a f low and f low pattern marks, sea cav es,

v iew of Omuroy ama and Izu Kogen plateau

Atagawa, Hokkawa Hokkawa Spa General access Engrav ed stone, v iew of Izu Kogen plateau

Hachinoy ama Volcano North Hachinoy ama Volcano General access Hachinoy ama scoria f all, v olcanic bombs, landf orm base and

scoria slope

Hachinoy ama Volcano Saganogawa Riv er Trail General access Lav a f low f rom Hachinoy ama v olcano and columnar joints

Hachinoy ama Volcano South Hachinoy ama Volcano Education purpose Lav a f low f rom Hachinoy ama v olcano

Hachinoy ama Volcano Summit of Hachinoy ama Volcano Education purpose Hachinoy ama scoria cone, smmit and crater

Hachinoy ama Volcano West Hachinoy ama Volcano General access Landscape of Hachinoy ama scoria cone, scoria f all and

Kawagodaira ash

Hachinoy ama Volcano West Hachinoy ama Volcano Education purpose lav a f rom Hachinoy ama v olcano and debris f low f rom Amagi

v olcano

Hosono Plateau Hosono Marsh General access Lahar f low and wetland

Hosono Plateau Southeastern slope of

Mt.Misujiy ama

General access Southeastern slope of Amagi v olcano and surrounding

panorama

Inatori Cape Kuronemisaki General access Inatori v olcano lav a f low, v iew of Inatori cape

Inatori Hasamiishi Rocks General access Amagi v olcano lav a and erosion landscape

Inatori Inatori Port Education purpose Inatori scoria cone, lav a f low and landscape

Inatori Mt.Sengensan General access Amagi v olcano landscape

Inatori North Inatori highschool Limited access Inatori scoria cone cross section and v olcanic bombs

Inatori South Cape Inatori Education purpose Amagi v olcano lav a f low, Nagano Daichi, Suzaki cape

(landscape)

Inatori West Cape Inatori General access Lav a f low of Amagi v olcano, platy joints dikes and stone

quarry ing ground

Kawazu Sev en Falls Deaidaru Waterf all General access Noborio Minami v olcano lav a and columnar joints

Kawazu Sev en Falls Ebidaru Waterf all General access base of lav a f low

Kawazu Sev en Falls Hebidaru Waterf all General access Noborio minami v olcano lav a and columnar joints, submarine

v olcanic deposition cov ered in lav a f low

Kawazu Sev en Falls Kamadaru Waterf all General access Noborio minami v olcano lav a and columnar joints, submarine

v olcanic deposition cov ered in lav a f low

Kawazu Sev en Falls Kanidaru Waterf all General access Noborio Minami v olcano lav a and columnar joints

Kawazu Sev en Falls Noboriominami f orestry road Research purpose Noborio minami v olcano lav a and columnar joints, submarine

v olcanic deposition cov ered in lav a f low

Kawazu Sev en Falls Odaru Waterf all General access Noborio minami v olcano lav a and columnar joints, submarine

v olcanic deposition cov ered in lav a f low

Kawazu Sev en Falls Satuta Gorge General access Noborio minami v olcano lav a and columnar joint

Kawazu Sev en Falls Shokeidaru Waterf all General access Noborio Minami v olcano lav a and columnar joints , dancing girl

of Izu (nov el setting) and Amagi Pass

Mine, Sawada Mine Hot Springs Water Spout General access Mine gey ser park

Mine, Sawada Sawada Limited access Stone quarry remnant

Mt. Kannony ama Mt. Kannony ama Education purpose Buddha engrav ings on submarine ash deposits

Mt. Kannony ama Northwest Hachinoy ama Volcano Education purpose Lav a f low of Ohira v olcano

Mt. Kannony ama West Mt. Kannony ama Education purpose Lav a f low of Ohira v olcano

Nashimoto, Yugano Nashimoto Education purpose Nashimoto limestone

Nashimoto, Yugano Nashimoto Education purpose Hachino y ama v olcano lav a and columnar joints

Nashimoto, Yugano Yugano Spa General access Valley and thermal springs created by submarine v olcanic

ejecta

Nawaji Nawaji Research purpose Nawaji glod deposit and mine

Nawaji Shobusawa coast Education purpose Ore deposit at topsoil lev el

Numanokawa Riv er East Numanokawa Riv er Education purpose Numanokawa Minami Volcano and columnar joints

Numanokawa Riv er Oginoiri f orestry road Research purpose Cross section of Numanokawa Minami scoria cone and lav a

f low

Numanokawa Riv er Oginoiri f orestry road Research purpose Numanokawa Minami Volcano and columnar joints

Oike, Koike Koike Volcano Education purpose Koike maar, v olcanic grav el f all

Oike, Koike Oike Volcano Education purpose Oike maar and land use

Oike, Koike West Oike Volcano Education purpose Oike Koike maars and grav el f all sites

Okusagano East Sandandaki waterf alls Research purpose Tuf f ring at Kannony ama East (cross section), cater lake

deposit, py roclastic f low f rom kawagodaira v olcano

Okusagano Kamisagano f orestry road Research purpose Cross section of scoria cone at upstream Sagano Riv er

Okusagano Kamisagano f orestry road Research purpose Saganogawa Jory u v olcano lav a and scoria f all, Grav el

deposit f rom Kannony ama Higashi v olcano

Okusagano Sandandaki waterf alls General access lav a f low f rom upstream Saganogawa Jory u v olcano

Sekiguchi, Kawakubogawa Riv er Ichinosawa f orestry road Education purpose Kawakubogawa scoria cone cross section and lav a f low

Sekiguchi, Kawakubogawa Riv er Sekiguchi Education purpose Sekiguchi scoria cone cross section and lav a f low

Sekiguchi, Kawakubogawa Riv er Yogaibashi bridge Education purpose Rocks, boulders and cany on

Shiranutanoike Pond Shiranutanoike Pond General access Freshwater pind at land slip area

Source of Shiratagawa riv er Junction of Shirata f orestry road Education purpose Sekiguchi Jory u Scoria Cone and lav a f low

Source of Shiratagawa riv er Shirata f orestry road Limited access Shirata sulf ur mine and ore

Ay utsubo Falls Ay utsubo Falls General access Cross section of Mishima lav a, lav a tree mold and loam lay er

Ay utsubo Falls Harabun ancient tomb General access Stone sarcophagus f rom Shirahama tuf f , stone house built

with Mishima lav a

Ay utsubo Falls Warikozuka-Inarijinja Shrine General access Mishima lav a f low

Kakitagawa Riv er Kakitagawa Riv er General access Spring water env ironment and ecosy stem f rom Mt. Fuji

Kakitagawa Riv er Mt.Honjoy ama General access Yokosegawa alluv ial f an and Kakitagawa, Kanogawa f low

Kitaizu Area

Kannami Area

Kawazu

Higashiizu Area

Kiy ozumi Green Area, Maruike Pond Maruike Pond General access Mishima springwater and use

Kiy ozumi Green Area, Maruike Pond Sakaigawa Kiy ozumi Green Area General access Mishima spring water

Kubo waterspring Kubo waterspring General access Springwater f rom Mt. Fuji, and Gotenba mudf low

Mishima Komoike Pond, Shirataki Park General access Springwater

Mishima Mishima Taisha Shrine General access Local belief associated with v olcanoes

Mishima North Mishima Station General access Cross section of Mishima lav a

Mishima Rakujuen Park, Genbeigawa Riv er General access Top section of Mishima Lav a and spring water

Momozawagawa Riv er Suijinja Shrine General access spring water f rom Ashitakay ama v olcano and belief s

Momozawagawa Riv er Tsurubeotoshi waterf all General access waterf all on platy joints created by Ashitaka v olcnism

Momozawagawa Riv er Yato watersprings Education purpose Ashitakay ama spring water site used f or school trip

Mt. Kanukiy ama Mt.Kanukiy ama Trail General access Submarine v olcanic ejecta

Mt. Kanukiy ama Summit of Mt.Kanukiy ama General access landscapes of Numazu area

Nagakubo Ushigaf uchi gorge General access waterf all on Mishima lav a

Nagakubo Yoroigaf uchi gorge General access waterf all on Mishima lav a

Nishiura Nishiura Education purpose Flank of Darumay ama v olcano

Ohira Deziroy ama Education purpose lock gate

Ohira Flood bank of Kanogawa Riv er Education purpose Embankment structure, history of Ohira region, landf orms of

Taga and Hakone v olcanoes

Ohira Himoriy ama Education purpose lock gate

Senbonhama, Ushibusey ama East Ushibusey ama General access Submarine lav a dome of rhy olite at seaside clif f , tsunami

related local belief s at Oasa shrine

Senbonhama, Ushibusey ama Gany udo Education purpose Old f ishing v illage, Kanogawa riv ermouth and By uo v iew, cros

relief of submarine v olcanoes

Senbonhama, Ushibusey ama Senbonhama, Numazu Port General access By uo and tsunami prev ention structures, v iew f rom

Senbonhama, Ushibusey ama Shimokanuki Education purpose Lake created by the Ansei Tokai earthquake

Senbonhama, Ushibusey ama West Ushibusey ama Research purpose Submarine lav a dome of rhy olite at seaside clif f

Sizuura, Uchiura Awashima Island General access Volcanic neck

Sizuura, Uchiura Kuchino Limited access Volcanic ash, pumice, and crosslamina deposited in submarine

Sizuura, Uchiura Shishihama Limited access Submarine v olcanic neck and columnar joint, tsunami

Sizuura, Uchiura Tabi Education purpose Submarine v olcanic deposition, dike, and quarry ing marks

Sizuura, Uchiura Uchiura Education purpose Outlet of Kanogawa drainage canal

Southern f oot of Ashitakay ama

Volcano

Kawakubo Education purpose Relict of Ansei Tokai earthquake

Southern f oot of Ashitakay ama

Volcano

Kumado Education purpose Temple that recorded the most recent eruption of Mt. Fuji and

Meiji era document repository

Southern f oot of Ashitakay ama

Volcano

Numazu IC Education purpose Alluv ial f an at Darumay ama f lank, v iew towards Izu

Southwest f oot of Hakone Volcano Fuy odai Education purpose Secondary tuf f ring at py rocalstic deposition of Hakone

Southwest f oot of Hakone Volcano Tsukahara Education purpose Py roclastic f low and crosss section of Hakone v olcanic

products, Mishima pumice and land use of py roclastic

Surugadaira Surugadaira General access Alluv ial f an at v olcanic f lank and v iew of Izu Peninsula

Cape Hagachizaki North Cape Hagachizaki General access large clif f of thermally weathered rocks

Irozaki Fault Irozaki Fault Education purpose Activ e f ault and Izu Hanto Oki earthquake

Irozaki, Ikenohara Irojinja Shrine General access Erosiv e landscape of submarine v olcanic deposits and local

Irozaki, Ikenohara Irozaki Port General access Submarine v olcanic ejecta and landf orm

Irozaki, Ikenohara Okuiro coast General access Cross section of submarine v olcano, cross section of Nanzaki

Irozaki, Ikenohara Yusuge Park General access Nanzaki v olcano landscape

Mera, Koura Cape Nagahaimisaki Limited access Submarine v olcanic ejecta and cross lamina

Mera, Koura Cape Ry uzaki General access Submarine v olcanic ejecta and dikes

Mera, Koura Cape Shirasaki General access Submarine v olcanic ejecta and bedding pattern

Mera, Koura Koura 33 Kannnons General access Submarine v olcanic ejecta and stone Buddha

Mera, Koura Mera General access Submarine v olcanic ejecta and dike, v olcanic neck, landscape

created by Jaishi v olcano

Mera, Koura Mera Pass Education purpose Jaishi v olcano and landscape, contrasting landscape

Okuiro Coast Cape Mitsuishimisaki General access Submarine v olcanic ejecta and dike

Okuiro Coast Iruma General access Submarine v olcanic ejecta, v olcanic necks, possible tsunami

Okuiro Coast Iruma Senjojiki General access Submarine v olcanic ejecta and wav e cut bench

Okuiro Coast Nakagi General access Submarine v olcanic ejecta and v olcanic neck, remnannt of

Izu Hanto Oki earthquake

Okuiro Coast Tosakaiwa Rocks General access Submarine v olcanic ejecta and dike

Okuiro Coast Yoshida General access Submarine v olcanic ejecta

Shimogamo Spa Kano Limited access Stone quarry ing ground (tuf f )

Tenjinbara, Jaishi Icchoda Education purpose Jaishi v olcano and land use

Tenjinbara, Jaishi Ihama Education purpose Jaishi v olcano and landscape submarine v olcanic ejecta

Tenjinbara, Jaishi Jaishi General access Hebiishi (strange stone f ormation)

Tenjinbara, Jaishi Ochii Education purpose Jaishi v olcano and landscape, submarine v olcanic ejecta

Tenjinbara, Jaishi Oike Marsh Education purpose Undulated landscape and wetland abov e Jaishi v olcano

Tenjinbara, Jaishi Tenjinbara Education purpose Jaishi v olcano and land use

Yumigahama Beach East Yumigahama General access Submarine v olcanic ejecta and cross section and erosiv e

Yumigahama Beach Midakutsu General access Submarine v olcanic ejecta and sea cav e

Yumigahama Beach Shimogamo Spa General access Hot spring and geothermal energy use

Yumigahama Beach Yumigahama Beach General access Sand spit and sand beach f ormation

Cape Koganezaki Cape Koganezaki General access panorama at Koganezaki cape: thermally weathered clif f , dike,

Dugashima, Nishina Port Cape Ajomisaki General access Submarine scoria cone and pumice stone

Dugashima, Nishina Port Cape Toumy ogasaki, Tago General access Cross sectionof submarine v olcano

Dugashima, Nishina Port Futo Coast General access Dikes

Dugashima, Nishina Port Kareno Park General access Lav a f low of submarine v olcano, submarine debris f low and

Dugashima, Nishina Port Near Nishina elementary school Limited access Pillow lav a of Nishina Group

Dugashima, Nishina Port North Dogashima Coast General access Tombolo af f ect at Sanshiro island, submarine v olcanic ash

Dugashima, Nishina Port Sawada Park General access Engrav ed mural at Shiraiwa, debris f low and pumice f rom

Dugashima, Nishina Port South Dogashima Coast General access Debris f low and pumice f rom submarine v olcanoes, open

Kitaizu Area

Nishiizu Area

Minamiizu Area

Kitaizu Area

Ikeshiro, Chokuroy ama Volcano Chokuro f orestry road Research purpose Submarine v olcano deposit and dike

Ikeshiro, Chokuroy ama Volcano Chokuro f orestry road Research purpose lav a f low f rom Chokuro

Ikeshiro, Chokuroy ama Volcano Ikeshiro Education purpose Submarine v olcanic ejecta, Mangan mine

Iwachi, Ishibu, Kumomi Iwachi General access Oumice lay er f rom submarine v olcano and inlet

Iwachi, Ishibu, Kumomi Iwachitoge Pass General access Submarine v olcanic ejecta, Iwachi Pass f ault and clastic dike

Iwachi, Ishibu, Kumomi Kumomi Port General access Pumice of submarine v olcano and Eboshiy ama

Iwachi, Ishibu, Kumomi Mt. Eboshiy ama General access Volcanic neck and panorama

Iwachi, Ishibu, Kumomi Muroiwado General access Pumice and lav a f rom submarine v olcanoes, stone quarry

Iwachi, Ishibu, Kumomi Near Kumomi Campingsite General access landscapes near Eboshiy ama and Senganmon

Iwachi, Ishibu, Kumomi Senganmon Rocks General access Crosss section of submarine v olcano

Iwachi, Ishibu, Kumomi South Ishibu General access Groundwater of Jaishi v olcano and rice terrace

Kadono Kadono Research purpose Kadono f ault landscape, land use

Koshimoda Koshimoda coast Education purpose Cross section of andesite of Koshimoda

Koshimoda Near Koshimoda Education purpose Andesite of Koshimoda

Matsuzaki, Sakurada Bentenjima Island General access Subaqueous lav a and tsunami prev ention measure

Matsuzaki, Sakurada Ena Education purpose Ena limestone

Matsuzaki, Sakurada Sakurada Education purpose v olcaic turbidite

Nishina Pass, Nekkodake Volcano Nishi Amagi highland Education purpose Volcanic land f ormation and land use, v iew towars Ugusu

Nishinagawa Riv er, Hozoin Temple Ishiki General access Pillow lav a of Nishina Group, dike

Nishinagawa Riv er, Hozoin Temple Near Deai Education purpose Turbidite and microf ossil

Nishinagawa Riv er, Hozoin Temple Nikkeikogy o stone pit Research purpose Debris f low and ash f rom submarine v olcanism,

Nishinagawa Riv er, Hozoin Temple West Hozoin Temple Research purpose Turbidite and crustal motion induced clif f f ormation

Nishinagawa Riv er, Hozoin Temple West Hozoin Temple Research purpose Hozoin limestone, Unconf ormity between Shirahama and

Odoi Odoi Coast Education purpose Daruma v olcano lav a, pumice f rom other(external) source

Ojiro, Miy agahara Miy agahara Education purpose large sacle land slip and Miy agahara basin, deep later water

Ojiro, Miy agahara Ojiro Education purpose large sacle land slip and Miy agahara basin

Seigoshi Mine Seigoshi Mine Limited access Goldmine remnant

Toi Gold Mine Gantsuki Tensho Goldmine General access Goldmine remnant

Toi Gold Mine Near Kamay ashiki Research purpose Alkali basalt and intrusiv e rock (dike) f ormation

Toi Gold Mine Toi Gold Mine General access Goldmine remnant, repository

Ugusu mine Ugusu mine Limited access Silica stone, and ore

Darumay ama Volcano Darumay ama Highland General access landscape panorama

Darumay ama Volcano North Darumay ama Volcano General access landscape panorama

Funabara Amagi Dome Education purpose Lav a plateau of Funabara v olcano

Hiekawa, Kashiwatoge Pass Kashiwatoge Pass Education purpose Lav a dome and obsidian

Hiekawa, Kashiwatoge Pass Mukai Education purpose Submarine pumice lay er, submarine lav a dome

Hinata Kajiy ama Education purpose Remnants of collapse caused by Kitaizu earthquake

Hinata Kajiy ama Turbidite Education purpose Turbidiet and ash f low f rom Kajiy ama

Hinata South Lake Sagiriko Education purpose Hinata tuf f ring and activ e f ault

Izunagaoka Kitaema Ancient Grav es General access Kitaema tunnel tombs, submarine v ocanic products, v olcanic

neck and columnra joints

Izunagaoka Mamanoue General access kanogawa drainage canal and repository

Izunagaoka Minamiema General access Markings of the Kitaizu Erathquake

Kitaomi Nakaizu winery Education purpose Usami v olcano lav a f low landscape

Kitaomi Upstream of Nishikawa Riv er Research purpose Lav a f rom Usami Volcano

Mt. Joy ama, Mt. Katsuragiy ama Mt. Joy ama General access Volcanic necks and surrounding landscapes

Mt. Joy ama, Mt. Katsuragiy ama Mt. Katsuragiy ama General access Volcanic necks and surrounding landscapes

Mt. Joy ama, Mt. Katsuragiy ama Mt. Shiratoriy ama Limited access Volcanic neck and columnar joints

Mt. Joy ama, Mt. Katsuragiy ama Omuro Education purpose Volcanic neck and columnar joints

Mt. Joy ama, Mt. Katsuragiy ama Yuhidaki waterf alls General access Columnar joint and waterf all

Ohito, Shuzenji Kumasaka Education purpose Kanogawa memorial park, Kanogawa Ty phoon, Kumasak and

adjacent areas

Ohito, Shuzenji Mt.Suishozan Education purpose Kanogawa and pearls

Ohito, Shuzenji Ohitobashi Bridge Education purpose kanogawa Ty phoon and Ohitobashi bridge history , f lodding

relics and f lood control schemes

Ohito, Shuzenji Shuzenjibashi Bridge General access Shuzenji bridge and Kanogawa ty phoon

Ohito, Shuzenji Ury uno Limited access Ohito goldmine remnant

Shimoshiraiwa, Kadono Kadono Education purpose Turbidite

Shimoshiraiwa, Kadono Shimoshiraiwa General access calcareous sandstone clif f

Shimoshiraiwa, Kadono Tashiro Education purpose Turbidite, sill

Shuzenji Spa Asahidaki waterf all General access Volcanic neck

Shuzenji Spa Shuzenji Spa General access Pumice f rom submarine v olcanism, unique hot spring town

South Niray ama Pass South Niray ama Pass Education purpose Taga v olcano lav a f low

South Niray ama Pass West Niray ama Pass Education purpose Ukihashi f ault landscape, f ault lake

Takatsukay ama Volcano,

Sukumoy ama Volcano

Chojagahara Volcano Education purpose Chojagahara maar, ejecta and Sukumoy ama scoria cone

Takatsukay ama Volcano,

Sukumoy ama Volcano

Sukumoy ama Volcano General access Cross section of Sukumoy ama scoria cone, v olcanic ash

f rom Chojagahara

Takatsukay ama Volcano,

Sukumoy ama Volcano

Tawarano basin Research purpose Tawarano basin, pumice and ash f rom Hakone

Ukihashi North Ukihashi Education purpose Volcanic ash f rom Hakone and Ky ushu

Ukihashi Ukihashi Education purpose Ukihashi basin

Yokoy ama, Umegi Umegi Education purpose Sandstone/mudstone f rom the last sea of Izu

Yokoy ama, Umegi Yokoy ama Research purpose Sandstone/mudstone and grav el f rom the last sea of Izu

Funay ama Funay ama Coast Education purpose Daruma v olcano lav a f low

Heda Cape Mihamamisaki General access Sand spit, marine aquarium of Suruga bay , anchor of Diana

(Russian ship) , lav a f low and eroded landscape of Daruma

v olcano

Heda Heda General access Sand spit, Daruma v olcano deposition landf orm, Spider carb

catch

Heda South Mihama Education purpose Daruma v olcano lav a f low

Nishiizu Area

Osezaki Heda

Area

North Nakaizu

Area

Ita North Ita Education purpose Ita v olcano lav a f low, sand spit and My ojin pond

Ita South Ita General access Ita v olcano lav a f low, sand spit and My ojin pond

Osezaki Cape Osezaki General access Sand-spit and f reshwater lens (kamiike)

Osezaki South Cape Osezaki Limited access Osezaki v olcano lav a and Osezaki v ent

Sanagiy ama, Kinkanzan Mt.Kinkanzan General access landscape panorama

Sanagiy ama, Kinkanzan Mt.Sanagiy ama Education purpose Cross section and cross sectional lay er of v olcano

Cape Tsumekizaki Takanba coast General access Coastal uplif t, erosion of sea cav e, disatnt v iew of

Cape Tsumekizaki Tsumekizaki coast General access Submarine debris f low

Cape Tsumekizaki West Tsumekizaki General access Sill and columnar joints

Kisami, Toji Kisami Beach General access Submarine debri f low and v olcanic bombs with chiiled

Kisami, Toji Ry ugu Sea Cav e General access Open top sea cav e, submarine scoria lay er, pothole

Kisami, Toji Toji Sand Ski Area General access Sand acculumation on slope, submarine debris and lav a,

v olcanic bombs with chiiled margin. Dikes, landscape of

Rendaiji Rendaiji Spa General access Mine remnant, ht spring town

Shimoda Port Kakisaki Bentenjima Island General access Cross lamina, trace f ossils, wav e cut bench, history of

Shimoda Port Mt. Nesugatay ama General access Volcani neck, View of Shimoda port and Suzaki cape

Shimoda Port Mt. Shimodaf uji General access Volcanic neck

Shimoda Port Shimoda Port General access Shimoda Fuji and Nesugata y ama, v iew of Suzaki cape,

Shimoda Port Urban area of Shimoda city General access Stone walls of submarine v olcanic deposits, history of

Shirahama Coast Shirahama Coast General access Calcareous sandstone and open top sea cav e

Shirahama Coast Shirahamajinja Shrine General access Volcanic legend associated with 832 AD Miy akejima eruption

and 838 AD Kozujima eription

Suzaki Ebisujima Island General access Subaqueous v olcaniclastic f low and ash f low, ritual site

Amagitoge Pass Hacchoike Pond General access Fault slip lake

Amagitoge Pass Hacchoike trail Limited access Scoria cone at Kanten f orestry road

Amagitoge Pass Hontani f orestry road Limited access Lav a and platy joints of Amagi v olcano

Hachikuboy ama Volcano Joren Falls General access Lav a f low and lav a plteau of Hachikuboy ama

Hachikuboy ama Volcano Noguro Education purpose Lav a and lahar f low f rom Hachikuboy ama

Hachikuboy ama Volcano Southern f oot of Marunoy ama

Volcano

Education purpose Cross section of Maruy ama scoria cone

Hachikuboy ama Volcano Southwestern f oot of

Hachikuboy ama Volcano

Limited access Hachikuboy ama cross section and lav a, pumice f rom

Kawagodaira

Kawagodaira Volcano Jy abamigawa Riv er Limited access Cross section of Kawagodaira py roclastic and lahar f lows.

Obsidian at riv er v alley

Kawagodaira Volcano Kawagodaira Volcano Education purpose Pumice lay er near and at the kawagodaira crater

Kawagodaira Volcano South Ikadaba Limited access Remmant of Kanogawa Tuy phoon, Kawagodaira lahar

Kawagodaira Volcano South Ikadabashinden Education purpose Pumice lav a lay er and py roclastic f low of Kawagodaira

Kokushigoe Pass Kokushigoe Pass Education purpose Kokushigoe maar and explosion breccia

Kokushigoe Pass Nagano General access Kokushigoe Minami v olcano lav a plateau

Maruno Highland Iwanoy ama Volacano Education purpose Explosion breccia and lav a dome of Iwanoy ama, maars

Maruno Highland Manten no y u Spa Education purpose Kunoy ama scoria cone and Amagi v olcano lav a plateau

Mochikoshi mine Mochikoshi mine Limited access Goldmine remnant

Namesawa Namesawa Gorge General access Lav a and lahar f rom Namesawa v olcano, Esashinomine

v olcano lav a

Namesawa Roadside Station "Amagigoe" Education purpose Esashinomine v olcano lav a plateau, landscape created by

Hachikuboy ama scoria cone, Jindai sugi tree

Nishina Pass, Nekkodake Volcano Amagi stock f arm General access Volcanic landscape, land use pattern and pumice of

Kawagodaira

Nishina Pass, Nekkodake Volcano Nishina Pass to Nekkodake

Volcano

General access Volcanic landscape and lav a

Togasay ama Volcano Togasay ama Volcano Education purpose Lav a f low of Togasay ama v olcano, v iew towards Izu Kogen

plateau

Yugashima Nihy akumai Education purpose Volcanic ash and turbidite

Yugashima Seko Waterf alls General access Submarine v olcanoes and dikes

Yugashima Yoichizaka Education purpose Lav a plateau of Yoichizaka v olcano

Osezaki Heda

Area

Simoda Area

South Nakaizu

Area