Transcript Taal Philippines Erice presentation 14Sep2011

Recurring non-eruptive unrest at
Taal (Philippines)
R.U. Solidum, E.P. Laguerta and Taal Monitoring Team
Philippine Institute of Volcanology and Seismology
(PHIVOLCS)
Volcano Observatory Best Practices Workshop:
Near-term Eruption Forecasting
11-15 September 2011
Introduction to PHIVOLCS
– major activities
• Monitoring, warning and advisory services on
volcanic and earthquake hazards, including
tsunami
- national seismic network
- 6 volcano observatories
• Hazard mapping and risk assessment services
• Research and development
• Disaster preparedness and risk mitigation
services
Introduction to PHIVOLCS
– links (some)
•
Member of the Technical Working Group of the Disaster
Risk Reduction and Management Councils (DRRMC) at
National level and Regional to Provincial Level if present
in area
• Office of Civil Defense (OCD)
• Local governments
• Key government agencies – land use and development
planning; local governance; education
• Non-government organizations
• Media
Tectonic Setting of the Philippines
~300 volcanoes:
• 23 active
• 26 potentially
active
Taal Caldera
South
China
Sea
Metro Manila
Tagaytay City
Taal Caldera
Main Crater Lake
Taal Lake
Volcano Island
Historical Eruptions at Volcano Island
• 33 eruptions since 1572
• latest eruption: October 1977
Historical Eruption Sites
• Main Crater (1572, 1591, 16051611, 1634, 1635, 1641, 1645,
1749, 1754, 1790, 1808, 1825,
1842, 1873, 1874, 1878, 1903,
1904, 1911)
• Binintiang Malaki (1707, 1715)
• Binintiang Munti (1709, 1729)
• Pira-piraso (1731)
• Off Calauit (1716)
• Mt. Tabaro (1965, 1966, 1967,
1968, 1969, 1970, 1976, 1977)
Some Destructive eruptions of Taal
1754 (15 May-30 Nov) – Main Crater; Plinian; VEI 4;
?dead
1911 (27 Jan- 7 Feb) – Main Crater; Phreatic; VEI 3; 1335
dead
1965 (28 to 30 Sep) – Mt. Tabaro; Phreato-magmatic; VEI
4; ~200 dead
Taal base surge, 1965
Areas affected by base surges (1754)
Areas affected by 1754 base surge
Tagaytay City
Old Tanauan
Mt. Batulao
Old Lipa
Balayan
Calaca
Data Sources:
Arboleda and Ruelo, (1986);
Torres, (1989)
Agoncillo
Eruption site
Mt. Makulot
Old Taal
Lemery
Taal
0
20
kilometers
Areas affected by base surges (1911, 1965)
1911
1965
Eruption site
Eruption site
0
km
4
0
Areas affected by base surges
Data Sources:
Pratt (1911); Worcester (1912); Moore, Nakamura and Alcaraz, (1966); Moore
(1967); Arboleda and Ruelo, (198x)
km
4
Base Surge Hazard Map
At risk: ~5000 people on Volcano Island
at least 100,000 people around Taal Lake
Response Action Based on Alert Level
ALERT LEVELS
RESPONSE
Alert Level 1
Main Crater is off limits to the public because sudden explosions
may occur or toxic gases may accumulate. Volcano Island
residents and visitors must be aware and vigilant of the volcano’s
condition.
Alert Level 2
Main Crater, Daang Kastila and 1965-1977 Mt. Tabaro Eruption Site
are off limits to the public.
Selective evacuation – women, children and elderly at the Volcano
Island are advised to transfer to their relatives at the mainland.
Alert Level 3
Total evacuation of the Volcano Island.
Alert Level 4
Flank eruption – lakeshore barangays facing eruption sitel
Eruption site: Main Crater – lakeshore barangays of Talisay,
Tanauan, Agoncillo, Balete, San Nicolas and Laurel.
Additional areas to be evacuated shall be determined based on the
development of escalating activity and possible location of eruption
site.
Alert Level 5
Expansion of risk areas depending on the magnitude of eruption.
Taal Volcano Seismicity (1990-1999)
Pira-piraso Station
Taal Volcano Seismicity (2000-2011)
Description of some unrest in Taal
• 1991 Mar to Jul - increased seismicity up to 45 VT events/day;
some felt at Intensities I-V; intense bubbling at Main Crater
Lake (MCL); geysering at MCL; lake T increased by 2C
• 1992 Feb 14-28 - dramatic increase in seismicity with 2550 VT
events within 24hrs, several were felt; decreased to baseline
within 2 weeks; Volcano Island uplifted up to 20cm; fissuring at
northeastern slopes; intense bubbling at MCL; lake T increased
by 2C (Alert level 2 then 3 – evacuation of Volcano Island)
• 1994 Mar 11-31 - escalating increase in seismicity with
1550 VT events within 24hrs, several were felt at
Intensities I-II; inflation of Volcano Island up to 16cm;
fissuring at eastern slopes; intense bubbling at MCL; lake T
increased by 5C (Alert level 3 – evacuation of Volcano
Island)
SUMMARY OF SEISMIC SWARMS/UNRESTS AT TAAL VOLCANO
Description of some unrest in Taal
• 2010 Apr - June - increase in VT events, several were felt;
slight inflation of Volcano Island; bubbling at MCL; lake T
increased by 2-3C; increased steaming at Crater Lake (Alert
level 2 - Main Crater off limits)
• 2011 Apr-May – increase in VT events, several felt at
Intensities I-III; quakes from 4km to 1km beneath Volcano
island; preceded by CO2 flux of 4600 t/d in late March, 4
times background measurement (Alert level 2 – Main Crater
off limits)
Taal Volcano Seismicity (2005, 2008, 2010, 2011)
Precise Leveling at SE slope
CO2 Flux (2008-2011)
CO2 flux from ITER (Spain)-PHIVOLS collaboration
Graph from Arpa et al, 2011
Communication of Forecast
(via fax, email, web, phone)
NDRRMC
Head
VAAC
Tokyo
Darwin
CAAP
National
Local
Met Office
National
Local
PHIVOLCS
HQ
OCD
National
PHIVOLCS
Observatory
OCD
Region
DRRMC
Province
DRRMC
Media
National
CAAP – Civil Aviation Authority
of the Philippines
NDRRMC- National Disaster Risk
Reduction and Management
Council
OCD – Office of Civil Defense
OP- Office of the President
Media
Local
Public
City/Town
DRRMC
Village
DRRMC
NDRRMC
Members
OP
Awareness and Preparedness Activities
(Town of Laurel – 2008)
Awareness and Preparedness Activities
(Village of Bilibinwang, Agoncillo – 2008)
Village Captain
Civil Defense Director
Some on-going initiatives for Taal
•
Improvement of monitoring systems:
- seismic telemetry (currently 8 stations: 4SP, 4BB)
- deformation (currently 3cGPS, one e-tilt; precise leveling,
EDM)
- electromagnetism
- gas geochemistry (CO2)
- Main Crater Lake observations (chemistry, T)
* With international partners from NIED and Japanese
institutions (JICA-JST), EMSEV Group, ITER (Spain), others?
• Awareness and preparedness at local level with province and
OCD Region
•
Advocacy for appropriate land use and development
planning
THANK YOU!
www.phivolcs.dost.gov.ph
PHIVOLCS Building, CP Garcia Ave.
UP Campus, Diliman, Quezon City
Tel 426-1468; Fax 9298366