volcanoes, earthquakes and tsunamis as geo-hazard concerns in the island of mindanao
TRANSCRIPT
Volcanoes, Earthquakes and Tsunamis as Geo-Hazard Concerns in the Island of Mindanao
Renato U. Solidum Jr and Ma. Mylene M. Villegas Philippine Institute of Volcanology and Seismology
Department of Science and Technology
The Mindanao Summit on Disaster Risk Reduction and Geo-Hazard Awareness
Cagayan de Oro City, February 18, 2012
Hazards
NATURAL HAZARDS
Geologic Hydro-meteorologic
• Volcanic eruptions Typhoons • Earthquakes Strong wind • Tsunamis Storm surge Landslides/mudflows Floods/flashfloods Erosion Drought, desertification Ground subsidence Extreme temperature warming, cooling Sea level change Salt-water intrusion
- threat that can cause loss of life, injury, property damage, loss of livelihood or services, social and economic disruption
1991 Explosive Eruption of Pinatubo: Can a similar eruption happen in Mindanao?
Tall eruption columns Pyroclastic flows downslopes at speeds >60kph
Thick ashfall caused collapse of roofs
Post-eruption lahars burying villages
Answer - YES
Volcanoes in
Mindanao
• 8 active volcanoes (erupted within the last 10,000 years)
Mt Parker – South Cotabato
Mt Parker Crater Lake
• Mt. Parker last erupted in 1641 • eruptions are similar to Mt. Pinatubo
Hazard Map of Mt. Parker
Active volcanoes in Mindanao
(eruption in the last 10,000 years) Name No. of Last eruption Location
Eruption Hibok-hibok 5 1949-1953 Camiguin
Ragang 7 1916 Lanao
Bud Daju 2 1897 Sulu
Musuan 1 1866 Bukidnon
Matutum 1 1911 S. Cotabato
Parker 1 1641 S. Cotabato
Makaturing 7 1882 Lanao
Leonard 1 1800 yrs ago Davao del N
Hibok-hibok 1951 eruption killed >500 people
Destructive Earthquakes: Can this happen in Mindanao?
Answer - YES
Magnitude 6.9
Negros
Earthquake
Liquefaction
Landslide
Collapse of Buildings – Intensity VIII
Earthquake Activity in Mindanao
Earthquake Generators and
Liquefaction Prone Areas in
Mindanao:
Active Faults (Red) Trenches (Violet)
Liquefaction (Yellow)
Earthquake-
triggered
Landslide
Hazard Map of
Mindanao
Large Tsunamis: Can these happen in Mindanao?
Miyako City
Natori City
From AP
From Kyodo News
Answer - YES
March 11, 2011
Japan Tsunami
Kessenuma From RUSolidum, PHIVOLCS
August 1976 Moro Gulf M7.9 Earthquake & Tsunami
Scope: Southwest Mindanao Casualties: Dead – 3,792 Missing – 1,937 Injured – 9,240 Houses Damaged: Total – 60,356 Estimated total damage: PhP 2.47 B
• Magnitude
7.9 quake
• Maximum
tsunami height
9 meters
Inundated villages Damaged houses & buildings
Transported bancas Crushed vehicles
Tsunami Impacts: 1976 August Earthquake
Tsunami causing earthquakes and tsunami events in eastern Mindanao
•1921 November 11 (Ms 7.4) •1924 April 14 (Ms 8.3) •1929 June 13 (Ms 7.2) •1952 March 19 (Ms 7.6) •1992 May 17 (Ms 7.1)
1921
1924
1929
1952
1992
Five (5) tsunami events 1 – 5 m high
One (1) tsunami event 6 m high
•1897 Sept 21 (Ms 7.5) 1897
Tsunami causing earthquake and tsunami event in northwestern Mindanao
•1917 January 31 (Ms 6.4) •1918 August 15 (Ms 8.0) •1923 March 2 (Ms7.2) •1976 August 17 (Ms 8.0) •2002 March 2 (Ms 6.8)
1917
1918
1923
1976
2002
Five (5) tsunami events 1 – 9 m high
Tsunami causing earthquakes and tsunami events in southern Mindanao
Tsunami Hazard Map – Davao Oriental
Tsunami Hazard Maps for Mindanao
Tsunami Hazard Map – Sultan Kudarat
Liquefaction Hazard Map
Surigao del Norte
Summary
• Moderate-sized to large explosive volcanic eruptions happened and can happen again in Mindanao
• Large-magnitude and destructive earthquakes happened and can happen again in Mindanao
• Large tsunamis happened and can happen again in Mindanao
• Explosive eruptions, destructive earthquakes and tsunamis are concerns that Mindanao should prepare for
Sudden onset, Infrequent events, Most often, destructive Let us focus on awareness raising Let us prepare communities
Please visit PHIVOLCS-DOST
booth
www.phivolcs.dost.gov.ph
For more info on geologic hazards maps, awareness and preparedness materials