LocalSource(CascadiaSubductionZone ... g l a s C o o s C os Cu ry 02 08 09 04 03 01 10 05 06 07 15...
1
N e w R iv e r N e w R i v e r Croft Lake Muddy Lake N e w R i v e r Pacific Ocean New Lake Lost Lake Laurel Lake 101 HOLLY LN BOYD LN HARVEY LN BETHEL MTN LN MCTIMMONS LN STEWART LN CHERRY LN 7-R RANCH LN MARPLE LN GILMAN LN BEARHEAD MTN LN GOSS LN 101 CASEY RD BUSTLING RD LOWER FOURMILE LN GREEN GULTCH LN WINDWARD LN THREE SISTERS LN HOFFER LN LAUREL RD DAVIS CRK LN LOIS LN PIONEER RD NEW LAKE LN CROFT LAKE LN SYDNAM LN DEW VALLEY LN 101 101 U P P E R F O U R MI L E L N B O W M A N L N W O O D S W A Y L N TWO MILE LN CR AN B E R R Y C R K LN 100 100 100 25 25 200 25 25 25 25 25 25 100 25 200 25 25 25 25 100 100 100 25 100 100 100 200 100 100 200 100 100 25 200 25 25 25 25 200 200 200 25 25 200 25 25 25 25 100 100 100 100 25 25 100 200 100 100 200 25 Bandon State Natural Area A A' B B' 124°24'0"W 124°24'0"W 124°26'0"W 124°26'0"W 124°28'0"W 124°28'0"W 43°2'0"N 43°2'0"N 43°0'0"N 43°0'0"N 42°58'0"N 42°58'0"N Software: Esri ArcGIS® 10.0, Microsoft® Excel®, and Adobe® Illustrator® Funding: This map was funded under award #NA09NW54670014 by the National Oceanic and Atmospheric Administration (NOAA) through the National Tsunami Hazard Mitigation Program. Map Data Creation/Development : Tsunami Inundation Scenarios: George R. Priest, Laura L. Stimely, Daniel E. Coe, Paul A. Ferro, Sean G. Pickner, Rachel R. Lyles Smith Basemap Data: Kaleena L.B. Hughes, Sean G. Pickner Map Production: Cartography : Kaleena L.B. Hughes, Sean G. Pickner, Taylore E. Womble Text : Don W.T. Lewis, Rachel R. Lyles Smith Editing: Don W.T. Lewis, Rachel R. Lyles Smith Publication: Deborah A. Schueller Map Date: 09/12/2012 Source Data: This map is based on hydrodynamic tsunami modeling by Joseph Zhang, Oregon Health and Science University, Portland, Oregon. Model data input were created by John T. English and George R. Priest, Department of Geology and Mineral Industries (DOGAMI), Portland, Oregon. Hydrology data, contours, critical facilities, and building footprints were created by DOGAMI. Senate Bill 379 line data were redigitized by Rachel R. Lyles Smith and Sean G. Pickner, DOGAMI, in 2011 (GIS file set, in press, 2012). Urban growth boundaries (2010) were provided by the Oregon Department of Land Conservation and Development (DLCD). Transportation data (2008) provided by Coos County were edited by DOGAMI to improve the spatial accuracy of the features or to add newly constructed roads not present in the original data layer. Lidar data are from DOGAMI Lidar Data Quadrangles LDQ-2009-43124- A4-Bandon and LDQ-2009-42124-H4-Langlois. Coordinate System: Oregon Statewide Lambert Conformal Conic, Unit: International Feet, Horizontal Datum: NAD 1983 HARN, Vertical Datum: NAVD 1988. Graticule shown with geographic coordinates (latitude/longitude). References: 2007 Working Group on California Earthquake Probabilities (WGCEP), 2008, The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2): U.S. Geological Survey Open-File Report 2007-1437 and California Geological Survey Special Report 203 [http://pubs.usgs.gov/of/2007/1437/]. Priest, G. R., 1995, Explanation of mapping methods and use of the tsunami hazard maps of the Oregon coast, Oregon Department of Geology and Mineral Industries Open-File Report O-95-67, 95 p. Priest, G.R., Goldfinger, C., Wang, K., Witter, R.C., Zhang, Y., and Baptista, A.M., 2009, Tsunami hazard assessment of the northern Oregon coast: a multi-deterministic approach tested at Cannon Beach, Clatsop County, Oregon: Oregon Department of Geology and Mineral Industries Special Paper 41, 87 p. Witter, R.C., Zhang, Y., Wang, K., Priest, G.R., Goldfinger, C., Stimely, L.L., English, J.T., and Ferro, P.A., 2011, Simulating tsunami inundation at Bandon, Coos County, Oregon, using hypothetical Cascadia and Alaska earthquake scenarios: Oregon Department of Geology and Mineral Industries Special Paper 43, 57 p. For copies of this publication contact: Nature of the Northwest Information Center 800 NE Oregon Street, #28, Ste. 965 Portland, Oregon 97232 telephone (971) 673-2331 http://www.naturenw.org Local Source (Cascadia Subduction Zone) Tsunami Inundation Map New River, Oregon 2012 Introduction The Oregon Department of Geology and Mineral Industries (DOGAMI) has been identifying and mapping the tsunami inundation hazard along the Oregon coast since 1994. In Oregon, DOGAMI manages the National Tsunami Hazard Mitigation Program, which has been administered by the National Oceanic and Atmospheric Administration (NOAA) since 1995. DOGAMI’s work is designed to help cities, counties, and other sites in coastal areas reduce the potential for disastrous tsunami-related consequences by understanding and mitigating this geologic hazard. Using federal funding awarded by NOAA, DOGAMI has developed a new generation of tsunami inundation maps to help residents and visitors along the entire Oregon coast prepare for the next Cascadia Subduction Zone (CSZ) earthquake and tsunami. The CSZ is the tectonic plate boundary between the North American Plate and the Juan de Fuca Plate (Figure 1). These plates are converging at a rate of about 1.5 inches per year, but the movement is not smooth and continuous. Rather, the plates lock in place, and unreleased energy builds over time. At intervals, this accumulated energy is violently released in the form of a megathrust earthquake rupture, where the North American Plate suddenly slips westward over the Juan de Fuca Plate. This rupture causes a vertical displacement of water that creates a tsunami (Figure 2). Similar rupture processes and tsunamis have occurred elsewhere on the planet where subduction zones exist: for example, offshore Chile in 1960 and 2010, offshore Alaska in 1964, near Sumatra in 2004, and offshore Japan in March 2011. CSZ Frequency: Comprehensive research of the offshore geologic record indicates that at least 19 major ruptures of the full length of the CSZ have occurred off the Oregon coast over the past 10,000 years (Figure 3). All 19 of these full-rupture CSZ events were likely magnitude 8.9 to 9.2 earthquakes (Witter and others, 2011). The most recent CSZ event happened approximately 300 years ago on January 26, 1700. Sand deposits carried onshore and left by the 1700 event have been found 1.2 miles inland; older tsunami sand deposits have also been discovered in estuaries 6 miles inland. As shown in Figure 3, the range in time between these 19 events varies from 110 to 1,150 years, with a median time interval of 490 years. In 2008 the United States Geological Survey (USGS) released the results of a study announcing that the probability of a magnitude 8-9 CSZ earthquake occurring over the next 30 years is 10% and that such earthquakes occur about every 500 years (WGCEP, 2008). CSZ Model Specifications: The sizes of the earthquake and its resultant tsunami are primarily driven by the amount and geometry of the slip that takes place when the North American Plate snaps westward over the Juan de Fuca Plate during a CSZ event. DOGAMI has modeled a wide range of earthquake and tsunami sizes that take into account different fault geometries that could amplify the amount of seawater displacement and increase tsunami inundation. Seismic geophysical profiles show that there may be a steep splay fault running nearly parallel to the CSZ but closer to the Oregon coastline (Figure 1). The effect of this splay fault moving during a full-rupture CSZ event would be an increase in the amount of vertical displacement of the Pacific Ocean, resulting in an increase of the tsunami inundation onshore in Oregon. DOGAMI has also incorporated physical evidence that suggests that portions of the coast may drop 4 to 10 feet during the earthquake; this effect is known as subsidence. Detailed information on fault geometries, subsidence, computer models, and the methodology used to create the tsunami scenarios presented on this map can be found in DOGAMI Special Papers 41 (Priest and others, 2009) and 43 (Witter and others, 2011). Map Explanation This tsunami inundation map displays the output of computer models representing five selected tsunami scenarios, all of which include the earthquake-produced subsidence and the tsunami- amplifying effects of the splay fault. Each scenario assumes that a tsunami occurs at Mean Higher High Water (MHHW) tide; MHHW is defined as the average height of the higher high tides observed over an 18-year period at the Port Orford tide gauge. To make it easier to understand this scientific material and to enhance the educational aspects of hazard mitigation and response, the five scenarios are labeled as “T-shirt sizes” ranging from Small, Medium, Large, Extra Large, to Extra Extra Large (S, M, L, XL, XXL). The map legend depicts the respective amounts of slip, the frequency of occurrence, and the earthquake magnitude for these five scenarios. Figure 4 shows the cumulative number of buildings inundated within the map area. The computer simulation model output is provided to DOGAMI as millions of points with values that indicate whether the location of each point is wet or dry. These points are converted to wet and dry contour lines that form the extent of inundation. The transition area between the wet and dry contour lines is termed the Wet/Dry Zone, which equates to the amount of error in the model when determining the maximum inundation for the each scenario. Only the XXL Wet/Dry Zone is shown on this map. This map also shows the regulatory tsunami inundation line (Oregon Revised Statutes 455.446 and 455.447), commonly known as the Senate Bill 379 line. Senate Bill 379 (1995) instructed DOGAMI to establish the area of expected tsunami inundation based on scientific evidence and tsunami modeling in order to prohibit the construction of new essential and special occupancy structures in this tsunami inundation zone (Priest, 1995). Time Series Graphs and Wave Elevation Profiles : In addition to the tsunami scenarios, the computer model produces time series data for “gauge” locations in the area. These points are simulated gauge stations that record the time, in seconds, of the tsunami wave arrival and the wave height observed. It is especially noteworthy that the greatest wave height and velocity observed are not necessarily associated with the first tsunami wave to arrive onshore. Therefore evacuees should not assume that the tsunami event is over until the proper authorities have sounded the all- clear signal at the end of the evacuation. Figure 5 depicts the tsunami waves as they arrive at a simulated gauge station. Figure 6 depicts the overall wave height and inundation extent for all five scenarios at the profile locations shown on this map. 0 20 40 Mile 0 30 60 15 Kilometer Tsunami Inundation Map Coos-17 Tsunami Inundation Maps for New River, Coos County, Oregon Plate 1 Do u g l a s C o o s C oos Curr y 02 08 09 04 03 01 10 05 06 07 15 11 12 13 14 17 16 OREGON Coos-10 Coos-11 Coos-12 Coos-13 Coos-14 Coos-15 Coos-16 Coos-17 Isthmus Slough Catching Slough Bullards Beach Leneve Coquille Coquille River Bandon New River Coos-01 Coos-02 Coos-03 Coos-04 Coos-05 Coos-06 Coos-07 Coos-08 Coos-09 Lakeside West Lakeside East Saunders Lake Haynes Inlet Coos Bay - North Bend Coos River North Coos River South Charleston - Cape Arago Barview - South Slough Legend State Park Senate Bill 379 Line Building Footprint Urban Growth Boundary Simulated Gauge Station 6 Profile Location Elevation Contour (25 ft intervals up to 200 ft) U.S. Highway 101 Fire Station Police Station School Hospital/Urgent Care Clinic Improved Road State Highway 241 XXL Wet/Dry Zone 1,200 ~9.1 650 to 800 ~9.0 425 to 525 ~8.9 300 ~8.7 1,050 to 1,200 ~9.1 Earthquake Size Maximum Slip Range (ft) Time to Accumulate Slip (yrs) Earthquake Magnitude Average Slip Range (ft) 118 to 144 XXL 59 to 72 72 to 98 L 36 to 49 46 to 62 M 23 to 30 30 to 36 S 13 to 16 115 to 144 XL 56 to 72 Occurrence and Relative Size of Cascadia Subduction Zone Megathrust Earthquakes Figure 3: This chart depicts the timing, frequency, and magnitude of the last 19 great Cascadia Subduction Zone events over the past 10,000 years. The most recent event occurred on January 26, 1700. The 1700 event is considered to be a “medium sized” event. The data used to create this chart came from research that examined the many submarine landslides, known as “turbidites,” that are triggered only by these great earthquakes (Witter and others, 2011). The loose correlation is “the bigger the turbidite, the bigger the earthquake.” STATE OF OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES www.OregonGeology.org Larry Givens, Governing Board Chair Vicki S. McConnell, Director and State Geologist Andree V. Pollock, Assistant Director Geologic Survey and Services Rachel R. Lyles Smith, Project Operations Manager Ian P. Madin, Chief Scientist Tsunami Inundation Map Index Data References Cascadia Subduction Zone Setting Figure 1: This block diagram depicts the tectonic setting of the region. See Figure 2 for the sequence of events that occur during a Cascadia Subduction Zone megathrust earthquake and tsunami. Estimated Tsunami Wave Height through Time for Simulated Gauge Station Figure 5: This chart depicts the tsunami waves as they arrive at the selected reference point (simulated gauge station). It shows the change in wave heights for all five tsunami scenarios over an 8-hour period. The starting water elevation (0.0 hour) takes into account the local land subsidence or uplift caused by the earthquake. Wave heights vary through time, and the first wave will not necessarily be the largest as waves interfere and reflect off local topography and bathymetry. No Gauge Station For Map Extent How Tsunamis Occur Displaced and uplifted Pacific Ocean water rushes in all directions. D E Along the Oregon coast, tsunami waves run up onto the land for several hours. Because the two plates are stuck in place at the “locked zone,” strain builds up over time and the North American Plate bulges up. B Eventually the locked zone ruptures and causes a great earthquake. The sudden slip of the two plates displaces Pacific Ocean water upward and creates a tsunami. C Figure 2: The North American Plate rides over the descending Juan de Fuca Plate at a rate of approximately 1.5 inches per year. A Figure 6: These profiles depict the expected maximum tsunami wave elevation for the five “tsunami T-shirt scenarios” along lines A-A' and B-B'. The tsunami scenarios are modeled to occur at high tide and to account for local subsidence or uplift of the ground surface. Maximum Wave Elevation Profiles 1:12,000 Scale Figure 4: The table and chart show the number of buildings inundated for each “tsunami T-shirt scenario” for cities and unincorporated portions of the map. Buildings within Tsunami Inundation Zones
Transcript of LocalSource(CascadiaSubductionZone ... g l a s C o o s C os Cu ry 02 08 09 04 03 01 10 05 06 07 15...
New
River
Ne
wR
i ve
r
Croft Lake
MuddyLake
Ne
wR
ive
r
Pa
ci f
i cO
ce
an
NewLake
LostLake
Laurel Lake
101
H O L LY L N
B O Y D L N
H A R V E Y L N
BETHE L
MTN
LN
MC T I M MO N S L N
ST EW A RT L N
CH E R R Y L N
7 - R R A N C H L N
MA R P L E L N
G I L M A N L N
B E A R HE A D M T N L N
G O S S L N
101
CA
SE
YR
D
BU
ST
LI N
GR
D
L O W E R F O U R M I L E L N
G R E E N G U LT CH L N
W I N D WA R D L NT H R EE S I S T E R S L N
CH INA C RK R D
WA
RB
LE
RR
D
H O F F E R L N
B O A K L N
LAU
RE
LR
D
D AV I SCR K
LN
LO I S LN
PIO
NE
ER
RD
N E W LA K E L N
CR OF T LA KE LN
SY
DN
AM
LN
D E W VA L L E Y L N
101
101
U P P E R F O U R M I L E L N
B O W M ANL N
W O O D S W AY L N
T W O M I L E L N
C R A N B E R R Y C R K L N
100 100
100
25
25
200
25
25
25
25
25
25
100
25
200
25
25
25
25
100
100
100
25
100
100
100
200
100
100
200
100
100
25
200
25
25
25
25
200
200
200
25
25
200
25
2525 25
100
100
100
100
25
25
100
200
100
100
200
25
Bandon StateNatural Area
A A'
B B'
124°24'0"W
124°24'0"W
124°26'0"W
124°26'0"W
124°28'0"W
124°28'0"W
43°2
'0"N
43°2
'0"N
43°0
'0"N
43°0
'0"N
42°5
8'0"
N
42°5
8'0"
N
Software: Esri ArcGIS® 10.0, Microsoft® Excel®, and Adobe®Illustrator®
Funding: This map was funded under award #NA09NW54670014 bythe National Oceanic and Atmospheric Administration (NOAA) throughthe National Tsunami Hazard Mitigation Program.
Map Data Creation/Development:Tsunami Inundation Scenarios: George R. Priest, Laura L. Stimely,Daniel E. Coe, Paul A. Ferro, Sean G. Pickner, Rachel R. Lyles SmithBasemap Data: Kaleena L.B. Hughes, Sean G. Pickner
Map Production:Cartography : Kaleena L.B. Hughes, Sean G. Pickner,Taylore E. WombleText : Don W.T. Lewis, Rachel R. Lyles SmithEditing: Don W.T. Lewis, Rachel R. Lyles SmithPublication: Deborah A. SchuellerMap Date: 09/12/2012
Source Data:This map is based on hydrodynamic tsunami modeling by Joseph Zhang,Oregon Health and Science University, Portland, Oregon. Model datainput were created by John T. English and George R. Priest, Departmentof Geology and Mineral Industries (DOGAMI), Portland, Oregon.
Hydrology data, contours, critical facilities, and building footprints werecreated by DOGAMI. Senate Bill 379 line data were redigitized by RachelR. Lyles Smith and Sean G. Pickner, DOGAMI, in 2011 (GIS file set, inpress, 2012).
Urban growth boundaries (2010) were provided by the OregonDepartment of Land Conservation and Development (DLCD).
Transportation data (2008) provided by Coos County were edited byDOGAMI to improve the spatial accuracy of the features or to add newlyconstructed roads not present in the original data layer.
Lidar data are from DOGAMI Lidar Data Quadrangles LDQ-2009-43124-A4-Bandon and LDQ-2009-42124-H4-Langlois.
Coordinate System: Oregon Statewide Lambert Conformal Conic, Unit:International Feet, Horizontal Datum: NAD 1983 HARN, Vertical Datum:NAVD 1988. Graticule shown with geographic coordinates(latitude/longitude).
References:2007 Working Group on California Earthquake Probabilities (WGCEP),2008, The Uniform California Earthquake Rupture Forecast, Version 2(UCERF 2): U.S. Geological Survey Open-File Report 2007-1437 andCalifornia Geological Survey Special Report 203[http://pubs.usgs.gov/of/2007/1437/].
Priest, G. R., 1995, Explanation of mapping methods and use of thetsunami hazard maps of the Oregon coast, Oregon Department ofGeology and Mineral Industries Open-File Report O-95-67, 95 p.
Priest, G.R., Goldfinger, C., Wang, K., Witter, R.C., Zhang, Y., and Baptista,A.M., 2009, Tsunami hazard assessment of the northern Oregon coast: amulti-deterministic approach tested at Cannon Beach, Clatsop County,Oregon: Oregon Department of Geology and Mineral Industries SpecialPaper 41, 87 p.
Witter, R.C., Zhang, Y., Wang, K., Priest, G.R., Goldfinger, C., Stimely, L.L.,English, J.T., and Ferro, P.A., 2011, Simulating tsunami inundation atBandon, Coos County, Oregon, using hypothetical Cascadia and Alaskaearthquake scenarios: Oregon Department of Geology and MineralIndustries Special Paper 43, 57 p.
For copies of this publication contact:Nature of the Northwest Information Center
800 NE Oregon Street, #28, Ste. 965Portland, Oregon 97232
telephone (971) 673-2331http://www.naturenw.org
Local Source (Cascadia Subduction Zone) Tsunami Inundation MapNew River, Oregon
2012
Introduction
The Oregon Department of Geology and Mineral Industries(DOGAMI) has been identifying and mapping the tsunamiinundation hazard along the Oregon coast since 1994. In Oregon,DOGAMI manages the National Tsunami Hazard MitigationProgram, which has been administered by the National Oceanicand Atmospheric Administration (NOAA) since 1995. DOGAMI’swork is designed to help cities, counties, and other sites in coastalareas reduce the potential for disastrous tsunami-relatedconsequences by understanding and mitigating this geologichazard. Using federal funding awarded by NOAA, DOGAMI hasdeveloped a new generation of tsunami inundation maps to helpresidents and visitors along the entire Oregon coast prepare forthe nextCascadia Subduction Zone (CSZ)earthquake and tsunami.
The CSZ is the tectonic plate boundary between the NorthAmerican Plate and the Juan de Fuca Plate (Figure 1). These platesare converging at a rate of about 1.5 inches per year, but themovementisnot smoothand continuous. Rather, the plates lockinplace, and unreleased energy builds over time. At intervals, thisaccumulated energy is violently released in the form of amegathrust earthquake rupture, where the North American Platesuddenly slips westward over the Juan de Fuca Plate. This rupturecauses a vertical displacement of water that creates a tsunami(Figure 2). Similar rupture processes and tsunamis have occurredelsewhere on the planet where subduction zones exist: forexample, offshore Chile in 1960 and 2010,offshore Alaskain 1964,near Sumatra in 2004, and offshore Japan in March 2011.
CSZ Frequency: Comprehensive research of the offshore geologicrecord indicates that at least 19 major ruptures of the full length ofthe CSZ have occurred off the Oregon coast over the past 10,000years (Figure 3). All 19 of these full-rupture CSZ events were likelymagnitude 8.9 to 9.2 earthquakes (Witter and others, 2011). Themost recent CSZ event happened approximately 300 years ago onJanuary 26, 1700. Sand deposits carried onshore and left by the1700 event have been found 1.2 miles inland; older tsunami sanddeposits have also been discovered in estuaries 6 miles inland. Asshown in Figure 3, the range in time between these 19 eventsvaries from 110 to 1,150 years, with a median time interval of 490years. In 2008 the United StatesGeologicalSurvey(USGS) releasedthe results of a study announcing that the probability of amagnitude 8-9 CSZ earthquake occurring over the next 30 years is10% and that such earthquakes occur about every 500 years(WGCEP,2008).
CSZ Model Specifications: The sizes of the earthquake and itsresultant tsunami are primarily driven by the amount andgeometry of the slip that takes place when the North AmericanPlate snaps westward over the Juan de Fuca Plate during a CSZevent. DOGAMI has modeled a wide range of earthquake andtsunami sizes that take into account different fault geometries thatcould amplify the amount of seawater displacement and increasetsunami inundation. Seismic geophysical profiles show that theremay be a steep splay fault running nearly parallel to the CSZ butcloser to the Oregon coastline (Figure 1). The effect of this splayfault moving during a full-rupture CSZ event would be an increasein the amount of vertical displacement of the Pacific Ocean,
resulting in an increase of the tsunami inundation onshore inOregon. DOGAMI has also incorporated physical evidence thatsuggests thatportions of the coastmay drop 4 to 10feet during theearthquake; this effect is known as subsidence. Detailedinformation on fault geometries, subsidence, computer models,and the methodology used to create the tsunami scenariospresented on this map can be found in DOGAMI Special Papers 41(Priestand others,2009) and 43(Witter and others, 2011).
MapExplanation
This tsunami inundation map displays the output of computermodels representing five selected tsunami scenarios, all of whichinclude the earthquake-produced subsidence and the tsunami-amplifying effects of the splay fault. Each scenario assumes that atsunami occurs at Mean Higher High Water (MHHW) tide;MHHWis defined as the average height of the higher high tides observedover an 18-year period at the Port Orford tide gauge. To make iteasier to understand this scientific material and to enhance theeducational aspects of hazard mitigation and response, the fivescenarios are labeled as “T-shirt sizes” ranging from Small,Medium, Large, Extra Large, to Extra Extra Large (S, M, L, XL, XXL).The map legend depicts the respective amounts of slip, thefrequency of occurrence, and the earthquake magnitude for thesefive scenarios. Figure 4 shows the cumulative number of buildingsinundated within the map area.
The computer simulation model output is provided to DOGAMI asmillions of points with values that indicate whether the location ofeach point is wet or dry. These pointsare converted to wet and drycontour lines that form the extent of inundation. The transitionarea between the wet and dry contour lines is termed theWet/Dry Zone, which equates to the amount of error in the modelwhen determining the maximum inundation for the eachscenario.Only the XXL Wet/DryZone isshown on this map.
This map also shows the regulatory tsunami inundation line(Oregon Revised Statutes 455.446 and 455.447), commonlyknown as the Senate Bill 379 line. Senate Bill 379 (1995)instructed DOGAMI to establish the area of expected tsunamiinundation based on scientific evidence and tsunami modeling inorder to prohibit the construction of new essential and specialoccupancy structures in this tsunami inundation zone (Priest,1995).
Time Series Graphs and Wave Elevation Profiles: In addition to thetsunami scenarios, the computer model produces time series datafor “gauge” locations in the area. These points are simulated gaugestations that record the time, in seconds, of the tsunami wavearrival and the wave height observed. It is especially noteworthythat the greatest wave height and velocity observed are notnecessarily associated with the first tsunami wave to arriveonshore. Therefore evacuees should not assume that the tsunamievent is over until the proper authorities have sounded the all-clear signal at the end of the evacuation. Figure 5 depicts thetsunamiwavesastheyarrive ata simulated gauge station. Figure6depicts the overall wave height and inundation extent for all fivescenariosat the profile locations shown on this map.
0 20 40 Mile
0 30 6015 Kilometer
Tsunami Inundation Map Coos-17Tsunami Inundation Maps for New River,
Coos County, Oregon
Plate 1
Dou
gla s
Coo
s
CoosCurry
02
08 09
04
03
01
10
0506
07
15
11
12 1314
17
16
OREGON
Coos-10Coos-11Coos-12Coos-13Coos-14Coos-15Coos-16Coos-17
Isthmus SloughCatching SloughBullards BeachLeneveCoquilleCoquille RiverBandonNew River
Coos-01Coos-02Coos-03Coos-04Coos-05Coos-06Coos-07Coos-08Coos-09
Lakeside WestLakeside EastSaunders LakeHaynes InletCoos Bay - North BendCoos River NorthCoos River SouthCharleston - Cape AragoBarview - South Slough
Legend
State Park
Senate Bill 379 Line
Building Footprint
Urban Growth Boundary
Simulated Gauge Station6
Profile Location
Elevation Contour(25 ft intervals up to 200 ft)
U.S. Highway101
Fire Station
Police Station
School
Hospital/Urgent Care Clinic
Improved Road
State Highway241
XXL Wet/Dry Zone
1,200 ~9.1
650 to 800 ~9.0
425 to 525 ~8.9
300 ~8.7
1,050 to 1,200 ~9.1
Earthquake SizeMaximum Slip
Range (ft)Time to
Accumulate Slip (yrs)EarthquakeMagnitude
Average SlipRange (ft)
118 to 144XXL 59 to 72
72 to 98L 36 to 49
46 to 62M 23 to 30
30 to 36S 13 to 16
115 to 144XL 56 to 72
Occurrence and Relative Size of Cascadia Subduction Zone Megathrust Earthquakes
Figure 3: This chart depicts the timing,frequency, and magnitude of the last 19great Cascadia Subduction Zone eventsover the past 10,000 years. The mostrecent event occurred on January 26, 1700.The 1700 event is considered to be a“medium sized” event. The data used tocreate this chart came from research thatexamined the many submarine landslides,known as “turbidites,” that are triggeredonly by these great earthquakes (Witterand others, 2011). The loose correlation is“the bigger the turbidite, the bigger theearthquake.”
STATE OF OREGONDEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIESwww.OregonGeology.orgLarry Givens, Governing Board ChairVicki S. McConnell, Director and State GeologistAndree V. Pollock, Assistant Director Geologic Survey and ServicesRachel R. Lyles Smith, Project Operations ManagerIan P. Madin, Chief Scientist
Tsunami Inundation Map Index Data References
Cascadia Subduction Zone Setting
Figure 1: This block diagram depicts the tectonic setting of the region. See Figure 2 for thesequence of events that occur during a Cascadia Subduction Zone megathrust earthquake andtsunami.
Estimated Tsunami Wave Height through Time for Simulated Gauge Station
Figure 5: This chart depicts the tsunami waves as they arrive at the selected reference point (simulated gauge station). It shows the change inwave heights for all five tsunami scenarios over an 8-hour period. The starting water elevation (0.0 hour) takes into account the local landsubsidence or uplift caused by the earthquake. Wave heights vary through time, and the first wave will not necessarily be the largest as wavesinterfere and reflect off local topography and bathymetry.
No Gauge Station For Map Extent
How Tsunamis Occur
Displaced and uplifted Pacific Oceanwater rushes in all directions.
D E
Along the Oregon coast, tsunami wavesrun up onto the land for several hours.
Because the two plates are stuck inplace at the “locked zone,” strain buildsup over time and the North AmericanPlate bulges up.
BEventually the locked zone rupturesand causes a great earthquake. Thesudden slip of the two plates displacesPacific Ocean water upward and createsa tsunami.
CFigure 2: The North American Platerides over the descending Juan de FucaPlate at a rate of approximately 1.5inches per year.
A
Figure 6: These profiles depict the expected maximum tsunami wave elevation for the five “tsunami T-shirtscenarios” along lines A-A' and B-B'. The tsunami scenarios are modeled to occur at high tide and to account forlocal subsidence or uplift of the ground surface.
Maximum Wave Elevation Profiles
1:12,000Scale
Figure 4: The table and chart show the number of buildings inundated for each “tsunami T-shirt scenario”for cities and unincorporated portions of the map.
Buildings within Tsunami Inundation Zones
