1. Volcano Observatory

2. Field Observation

3. Earthquake Detector

4. Data Analysis

POS PGA G. Anak Krakatau, Pasauran

III. THE 2010 MERAPI ERUPTION

• After 2004 Tsunami in Aceh, the Indonesian government made two important laws,

1. UU no. 24 Tahun 2007 on ”Disaster Management”

2. UU no. 26 Tahun 2007 on ”Spatial Planning”

• Based on these laws, disaster management paradigm is

changed, now the disaster management in Indonesia are focused on risk reduction in pre-disaster phase.

Merapi is geographically located at position 7⁰ 32.5’ S dan 110⁰ 26.5’ E, at an altitude of 2980 m msl (before 2010 crisis).

3

Merapi stratovolcano located 25-30 km north of Yogyakarta city-Indonesia, and in densely populated area. Merapi is one of the most active and dangerous volcanoes in Indonesia (more than 40,000 people living nearby the volcano). Eruptive activity during the 20th century typically reccured every 4 to 6 years (produce lava dome and pyroclastic flow) with VEI 1-3. The latest eruption 2010 , Merapi’s eruption had a VEI of about 4. CVGHM-Geological Ageny has a task to monitor its activity and issue early warning to the people around the volcano.

III. THE 2010 MERAPI ERUPTION

• Eruption in 19th century, its intensity relatively bigger, whereas eruption in 20th century is more frequent. The possibility of big eruption occurs once in 100 years (Newhall, 2000). Example : Scale of 2006 eruption was VEI 2.

• The early warning system at Merapi (as at all volcanoes in Indonesia) comprises 4 alert level and it is based on the analysis of instrumental and visual observation.

Chronology of The 2010 Eruption of Merapi

Alert Level Date ConditionsMERAPI ACTIVITIES

Merapi Crisis 2006 Merapi Crisis 2010

Awas 25 /10/ 2010

Will erupt soon, a critical situation that can lead to disaster at any time

With lava dome, Lava flow, and pyroclastic flowsSeismicity:MP=145Vul=4Rockfall=53Deformation rate =0 (since 24/04/06)

The eruption is effusive with constuction of lava domes, rockfall and pyroclastic flow.

Without lava dome, without lava flow, and without big rockfallsSeismicity:MP=588Vul=80Rockfall=194 Deformation rate=42 cm/day

Explosive eruption with pyroclastic flows and boom.

Siaga 21 /10 2010

All data indicate that the activity could soon lead to an eruption or to the circumstances that can lead to disaster

Increase in seismicity:MP=47x/day; Vul=4x/day;Rockfall=5x/day

Deformation rate=10cm/day

Increase in seismicity: MP=150x/day; Vul=17x/day;Rockfall=29x/day

Deformation rate =17cm/day

Waspada 20 /09 2010

Indication of increase in activity above normal condition with a clear trend pattern.

Increase in Sesimicity:MP=32x/day; Vul=3x/day;Rockfall=3x/day

Increase in sesimicity:MP=38x/day; Vul=11x/day;Rockfall=3x/day

Normal 17 /11 2007

Monitoring data on the daily average value (background data), there is no indication to increase.

• The early warning system at Merapi (as at all volcanoes in

Indonesia) comprises 4 alert level and it is based on the

analysis of instrumental and visual observation.

Level III

Level IV

Daily Count of Seismicity

Summit inflation only measured in southern side (>3m). Another side is stable.

DEFORMATION OF SOUTHERN FLANK

W S A

Erupt

7

“AWAS” Merapi (alert level IV)

25 October 2010, 06:00 am : SIAGA AWAS Safety zone out of 10 km in

radius from the summit of Merapi SO2 flux = 249 tons/day

26 October 2010, 5:02 pm : First eruption

www.klaten.go.id

Map of Merapi Hazard Zone (revised)

RecommendationOn 21 October CVGHM-Geological Ageny raised the alert from level II toIII due to an increased likelihood of eruption.

On 25 October , after seismicity and deformation increased, CVGHM-Geological Ageny raised the alert from level III to IV.

• Visitors and residents were prohibited from approaching the crater within a 10-km-radius

“AWAS” Merapi (alert level IV)

29 -30 October 2010 : Eruption was more explosive

3 November 2010 : The series of pyroclastic flows occurs that began at 11:11 am, an increase in SO2 flux measured by mini DOAS (reached 500 ton/hari)

4:05 pm : Safe zone out of 15 km in radius from the summit

5:30 pm : Pyroclastic flow travelled down to 9 km into K. Gendol (southern part)

Recommendation

On 3 November , a large eruption occured, CVGHM-Geological Ageny recommended extending the evacuation zone on the west and southFrom 10 km to 15 km, which increased the number of displaced people(> 100,000).

“AWAS” Merapi (alert level IV)

4 November 2010 : continuous and overscale tremor and also increasing SO2 mass in atmosphere reached more than 100 kilotons

safe zone out of 20 km from summit

5 November 2010 : Dome collapsed generating pyroclastic flows with traveling distance to 15 km from the summit into Kali Gendol.

OMI

Boston Globe

“AWAS” Merapi (alert level IV)

6 November 2010 : Tremor is still continuous and overscale SO2 mass reached the peak at 250

- 300 kiloton.

13 November 2010: Decrease in eruption intensity change in safe zone radius

No. Kabupaten Ancaman Bahaya Erupsi G. Merapi dalam radius dari puncak (km)

1 Sleman 20 (before: 20 km)

2 Magelang 15 (before: 20 km)

3 Boyolali 10 (before: 20 km)

4 Klaten 10 (before: 20 km)

“AWAS” Merapi (alert level IV)

19 November 2010 : Decrease in eruption intensity change in safe zone radius

No. KabupatenAncaman Bahaya Erupsi G. Merapi

dalam radius dari puncak (km)

1 SlemanWestern part K. Boyong 10Eastern part K. Boyong 15

2 Magelang 103 Boyolali 54 Klaten 10

“AWAS” Merapi (alert level IV)

LOKASI

MENINGGALRAWAT

INAP PENGUNGSI TITIK PENGUNGSIANLUKA

BAKARNON-LUKA

BAKAR TOTAL

SLEMAN 189 60 249 99 29958 151KULON PROGO 1597 11

YOGYAKARTA KOTA 1142 39BANTUL 2374 17

GUNUNG KIDUL 2401 17TOTAL DIY 189 60 249 99 37472 235

KLATEN 7 29 30 4321 147BOYOLALI 10 37 672 20

KAB. MAGELANG 52 92 16429 105KOTA MAGELANG 601 16

TEMANGGUNG 359 1

TOTAL JATENG 7 91 159 22382 289

TOTAL 196 151 249 258 59854 524

Total victims caused by Merapi crisis 2010 is 249 people (BNPB)

Maximum refugee reached 410.388 people (BNPB)

“SIAGA” Merapi (alert level III)

On 3 December 2010, the alert level was downgraded to Level III (siaga) from Level IV.

IV. Conclusion• Early warning (Level I - Level IV) is not to predict volcanic eruption (when and

how big the eruption will be), but each level depends on the level of activity and the potential hazards that may increase the hazard risk.

• Rapid population growth and development of settlements in Indonesia (including Merapi) increased vulnerability in geological hazard risk management.

• Volcanic Hazard Maps for all type-A volcanoes (volcanoes that have erupted at least one time since 1600) in Indonesia have been published and received by local governments.

• In a volcanic eruption hazard risk reduction required the cooperation of all parties, where people live around the volcano is the subject. Education to the community in anticipation of the threat of volcanic eruption hazards become a key so that people can live in harmony with volcanoes. Volcano is a blessing for the surrounding community. Volcanoes provide important in life and living: soil fertility, provide water, provide the magnificence, so that people can live in prosperity and peace.

Thank You …!