Training on Disaster Risk Reduction: The Role of DOST Regional Offices

3.4 Geological Hazards: Volcanoes and Volcanic Hazards Day-2, 11 December 2013

Ma. Mylene Martinez-Villegas PHIVOLCS VOLCANOES Mix-MATCH Beauty and Beast : Beauty

A B C

D E F Volcano: Beast

A B C

D E F Your group will be given photos, manila paper and tape. Identify the volcanoes. Use the manila paper provided. Arrange and paste the photos and labels following the example below . Volcano Photos Volcano Name Location Eruption in Quiet/Normal progress Volcanoes in the >300 volcanoes

23 classified as active

6 most active • Pinatubo • Taal • • Bulusan • • Hibok-hibok Volcanoes in the Philippines (~300 volcanoes: 23 active, 26 potentially active; ~ 170 eruptions for past 400 years))

Pinatubo 1991

Mayon 2009 Volcano Disasters

Volcano Year Casualties , Batangas 1754 Undetermined number; relocation of Taal, Talisay and Lipa 1911 1,200 1965 200 Mayon Volcano, Albay 1814 Undetermined number 1897 350 1993 77 (Bonga, Legaspi) Hibok-hibok, 1951 500 (Mambajao) Pinatubo, Pampanga- 1991 847 Tarlac-Zambales What is a VOLCANO?  a vent, hill or mountain from which molten or hot rocks with gaseous materials are ejected  can be craters, hills or mountains formed by removal of pre-existing material or by accumulation of ejected materials

MAYON VOLCANO

BULUSAN VOLCANO TECTONIC AND GEOGRAPHIC SETTINGS OF THE PHILIPPINES

Distribution of Volcanoes in the World Tectonic Setting of the Philippines

NORTHERN SAMAR Classification of Volcanoes (PHIVOLCS) ACTIVE: erupted w/in historical times (last 600 yrs); has written historical accounts or oral tradition erupted w/in the recent geological period ( ≤10,000 yrs) based on radiometric dating has volcanic seismicity

POTENTIALLY ACTIVE landform is young-looking but w/ no records or proof of eruption

INACTIVE no recorded eruptions long-period inactivity is evident from too much weathering & erosion of deep & long gullies (valleys) Active Volcanoes in the Philippines

Name No. of Date of Last LAT/LONG Location Eruptions Eruption Mayon ↸ 49 2006 13° 15.4'/123° 41.1' Albay, Bicol Region, L uzon Taal ↸ 33 1977 14° 00'/121° 00' Batangas, Canlaon ↸ 22 1996 10° 24.7/123° 7.9' Negros Occidental, Visay as Bulusan ↸ 14 2006 12° 47'/124° 03' Sorsogon, Bicol Region, Lu zon Ragang 9 1915 7° 41.5/124° 30.3' Bukidnon, Smith 6 1924 19° 32.5/121° 55' , Northern Luzon Hibok-Hibok ↸ 8 1949-1953 9° 12.2/124° 40.4 Camiguin Island, Mind anao Didicas 6 1978 19° 05'/122° 12' Cagayan, Northern Luzon Pinatubo ↸ 3 1991 & 1992 15° 08'/120° 21' Pampanga, Zambales & Tarlac, Luzon Babuyan Claro 3 ?1913 19° 31.5'/121° 57' Cagayan, Northern Luzon Bud Dajo 2 1897 5° 59'/121° 13' Sulu, Mindanao 1 1857 18° 50'/121° 52' Cagayan, Northern Luzon Cagua 1 1860 18° 13'/122° 07' Cagayan, Northern Luzon Banahao ↸ 1 ?1730 14° 04'/121° 29' Laguna & Quezon Province, Luzon Calayo (Musuan) 1 1866 7° 52'/125° 4.4' Bukidnon, Mindanao Iraya 1 1464 20° 29'/122° 01' Batanes Island, Northern Lu zon Iriga 1 ?1628 13° 28'/123° 28' Camarines Sur, Bicol Regio n, Luzon ? ?1939 11° 37'/124° 30' Leyte, Visayas Matutum ↸ 1 ?1911 6° 22'/124° 04' South Cotabato, Mindanao Parker ↸ 1 1641 6° 6.8'/124° 53.5' South Cotabato, Mindanao Makaturing ? ?? 7° 38.5'/124° 19' Lanao, Mindanao Leonard 1 1,800 Bp 7° 4.5'/126° 4' Davao, Mindanao Cabalian 1 135 Bp 10°17'13.2"/125 Southern Leyte °13.25' FORMS OF VOLCANOES

Controlled mainly by magma composition

EFFUSIVE EXPLOSIVE

Low SiO (BASALTIC) Intermediate 2 High SiO 2 (SILICIC) SiO 2 (ANDESITIC)

SULFUR DIOXIDE/SILICA CONTENT (SiO2) GeochemicalGeochemical----RheologicalRheological Guide Structures and Field Relationships

Figure 4.2 . Volcanic landforms associated with a central vent (all at same scale). TYPES OF VOLCANIC ERUPTION

Controlled mainly by magma composition (silica content) & volatile (gas) content

EFFUSIVE EXPLOSIVE Intermediate Low SiO (BASALTIC) 2 High SiO 2 (SILICIC) SiO 2 (ANDESITIC)

Etna, Sicily Mayon, Albay Redoubt, Alaska Type of Volcanic Eruption: PHREATIC

2000 Phreatic eruption, Mt. Usu, Japan  Steam-driven eruptions; contact of groundwater w/ hot country rocks (no 1984 Phreatic event at magma) Mayon Volcano  Usually precursory to magmatic eruptions

Thick ash column near 1976 Phreatic eruption Toya Spa, 10 April 2000 at Taal Volcano Eruption of Mt. Usu Type of Eruption: PHREATOMAGMATIC

Very violent eruption generated by the explosive contact of erupting magma with water Voluminous, slightly tall ash columns, laterally-projected pyroclastic currents (base surges) & blasts

1966 Taal Volcano phreatomagmatic phase Type of Eruption: STROMBOLIAN

Weak to violent eruption of gas-charged fluid magma Lava fountaining & flowing  So named from STROMBOLI VOLCANO that ejected lava bombs located off the coast of Sicily; has erupted continuously for thousands of years

Stromboli Volcano, Italy 2000 Mayon eruption Strombolian phase Type of Eruption: VULCANIAN

 Characterized by a dense cloud of ash-laden gas exploding from the crater and rising high above the peak  Can produce tall eruption columns (sometimes >20 km); pyroclastic flows, ashfall  Vulcanian type was discovered from studies of the activity, between 2 August 1888 and 22 March 1890, of Fossa cone at VULCANO in the Aeolian Islands, Italy.

1997 Soufriere Hills Eruption, Montserrat Vulcanian Phase Mayon 2000 eruption 1991 eruption of Pinatubo Volcano Type of Eruption: PLINIAN

Highly explosive, with dense clouds of gas and tephra being propelled upwards for many kilometres Form huge tall mushroom columns (maybe more than 40 km high), and pyroclastic flows Creates large volcanic calderas Figure 4.18 . Types of pyroclastic flow deposits. After MacDonald (1972), Volcanoes . Prentice- Hall, Inc., Fisher and Schminke (1984), Pyroclastic Rocks. S pringer-Verlag. Berlin. a. Collapse of a vertical explosive or plinian column that falls back to earth, and continues to travel along the ground surface. b. Lateral blast , such as occurred at Mt. St. Helens in 1980. c. “Boiling-over ” of a highly gas-charged magma from a vent. d. Gravitational collapse of a hot dome. e. Retrogressive collapse of an earlier, unstably perched ignimbrite . VOLCANIC HAZARDS

2000 eruption of Mayon Volcano Volcano-related phenomena/ processes that pose potential threat or cause negative impact to man, property & the environment, in a given period of time. VOLCANIC HAZARDS

Primary Volcanic Secondary Volcanic Hazards Hazards

Lava flows Lahars Pyroclastic flows Secondary explosions Ashfall or tephra fall Tsunami Volcanic gases Debris avalanche/ Fissuring Sector collapse Volcanic Hazard: ASHFALL or TEPHRA FALL

Gravitational settling of volcanic ash & fragments from the umbrella clouds of tall eruption columns & ashclouds of pyroclastic flows Dispersal depends on prevalent wind directions, column heights Impacts of Ashfall

Results to widespread infrastructural damages when thick Monitored

Pinatubo, Philippines, worldwide by 1991 aviation agencies due to potential jet engine failure to all types of aircraft Health hazard Impacts of Ashfall

Buildings destroyed by ballistic mudballs from the 2000 Mt. Usu Eruption Volcanic Hazard: Kilauea lava flow Low SiO2  Pahoehoe (Ropy) LAVA FLOW Lava

Incandescent rivers of hot molten rock (lava) Erupted from volcanic craters, fissures, during Hawaiian- Strombolian activity, lava dome eruptions From USGS Usually slow-moving for

moderate-high SiO 2 magma; fast-moving for

low SiO 2 magma (e.g. Hawaii lavas)

1969 Taal Volcano (Mt. Tabaro) Lava Flow Field Volcanic Hazard: LAVA FLOW

1993 Mayon lava flow Intermediate SiO2  Blocky Lava

2000 Mayon lava flow Intermediate SiO2  Blocky Lava Impacts of Lava Flow

Results in long term disuse of buried land

From USGS Volcanic Hazard: PYROCLASTIC FLOWS & SURGES

Turbulent mass of ejected fragmented volcanic materials (ash & rocks) + hot gases that flow downslope at very high speeds (30-700 kph) Deadliest of all volcanic hazards Volcanic Hazard: PYROCLASTIC FLOWS & SURGES

SOUFRIERE HILLS VOLCANO Montserrat Volcano Observatory • Show Pinatubo PF • Show Mayon PF

Impacts of Pyroclastic Flows & Surges

Burning & incineration of everything in the flow path Filling of river valleys w/ pyroclastic flow deposits

Mayon Volcano Ridge

Pinatubo Volcano: BEFORE

Ridge

Pinatubo Volcano: AFTER Impacts of Pyroclastic Flows & Surges

Hibok-Hibok Volcano, Camiguin Island, December 1951: 500 deaths Impacts of Pyroclastic Flows & Surges

1911 Taal Volcano eruption: 300 deaths from base surges, travels laterally outward from the base of an eruption column at 90-500 m/s, first recognized in 1947 in explosion mushrooms of underwater nuclear tests

Taal Volcano, 24 July 1966 Impacts of Pyroclastic Flows & Surges

base surge

Taal Phreatomagmatic Eruption, 1965 Volcanic Hazard: LAHARS

Bacolor, Pampanga, Pinatubo Volcano Yawa River, Albay, Mayon Volcano

Rapidly flowing thick mixture of volcanic sediments and water Triggered by rainfall, melting of craterial icecaps, lake breakout or hydrothermal “squeezing” Two Classes of Lahars

DEBRIS FLOW • high viscosity • solid fraction is 60- 80% by weight or >60% by volume Two Classes of Lahars

HYPERCONCENTRATED STREAMFLOW • has moderate viscosity •solid fraction 20- 60% by weight, 40- 60% by volume 1991 Impacts of Lahars

Burial Cutoff and Isolation Long-term siltation & related flooding

1992 DIZON MINES COMMUNITY

Sacobia-Bamban River Pampanga River Delta: 1992

 Lowermost reaches of Pasig-Potrero & Porac-Gumain clogged by new sediments  Siltation, clogging of delta rivers, preventing Orani drainage to Orani estuary, Manila Bay Pasig-Potrero/Porac-Gumain, Pampanga, Pinatubo Volcano

Volcanic Hazard: Gases

Basic components of magma or lava:

- Water (H 2O), Carbon Dioxide (CO 2) , Carbon Monoxide (CO), Hydrogen

Sulfide (H 2S), Flouride (F 2), Sulfur Dioxide (SO 2), Sulfuric Acid (H 2SO 4), etc.) Mostly toxic species

From USGS From USGS Impacts of Volcanic Gas

• Pollutes the atmosphere and causes acid rain • Causes vegetation, fish and animal kills, death

•Bubbling of water during 1969 eruption, Taal Lake, due to escaping gas from magma beneath the lake floor

USGS Volcanic Hazard: GROUND FISSURING

• due to movement of magma beneath the surface may be movement/ adjustments along faults accompanied by 1911 eruption fissure, Lemery, Batangas earthquakes

Caysasay Church sustained damages due to strong ground 2000 Mt. Usu eruption fissuring shaking Volcanic Hazard: DEBRIS AVALANCHE

Downslope movement of large-volume proportions of the volcanic flanks due to: movement of magma beneath the edifice (Bezymmiany-type)  adjustments along faults transecting volcanoes earthquakes (Bandai-type) Volcanic Hazard: DEBRIS AVALANCHE

Produces horseshoe-shaped crater, hummocky topography Devastation of tens or hundreds square kilometers of area at the volcano slopes & foot Volcanic Hazard: SEICHE / LAKE TSUNAMI

Formed by perturbations by eruptions, debris avalanches entering lakes, bays Taal 1911 & 1965 eruptions– generated seiches 2.5-4.7 m-high seiches that swept inshore for ca. 100 m

Effects of seiches along the lakeshore areas TYPICAL ERUPTION PRECURSORS Bulusan Volcano Alert Levels

Alert Level Criteria Interpretation

0 Background, quiet No eruption in foreseeable future

1 Low level of seismic, fumarolic, and Magmatic, tectonic or hydrothermal other unrest disturbance; no eruption imminent

2 Moderate level of seismic, other unrest Probable magma intrusion; could with positive evidence for involvement eventually lead to an eruption of magma

3 Relatively high and increasing unrest, Increasing likelihood of an eruption, including numerous low frequency possibly explosive, probably within days volcanic earthquakes, accelerating to weeks. ground deformation, increasing fumarolic activity.

4 Intense unrest, including harmonic Magma close to or at the earth’s surface. tremor and/or many “long-period”(i.e., Hazardous explosive eruption likely, low frequency) earthquakes and/or possibly within hours or days. dome growth and/or small explosions

5 Hazardous eruption in progress. Hazards in valleys and downwind. VOLCANIC HAZARDS ZONATION MAPS

 Show areas identified to be prone to a particular volcanic phenomena  Tool to gauge the degree of susceptibility of a given area to a particular hazard  Determine which areas should be evacuated and avoided during eruptions  Provide guidelines for long-range land use planning around volcanoes that take into account potential hazards from future eruption

Consideration of areas to be impacted by eruptions

• No settlements in Permanent Danger Zones (PDZ) • Evacuate and avoidance of additional hazardous areas during volcanic activities • Plan locations of facilities, settlements taking into account potential hazards from future eruptions MITIGATION MEASURES: DISASTER AWARENESS

Exhibits

Publications

Lectures/Conferences

Signages Posters

Pagpapalawak ng kaalaman ng komunidad ukol sa panganib TARGETS OF DISASTER AWARENESS PROMOTION …Local Government Officials, The Community… planners, developers……

…Media

…Teachers and Students Teach school children and PUBLIC what to do during and after occurrence of volcanic hazards BENEFICIAL EFFECTS OF VOLCANOES

Various forms/shapes BENEFICIAL EFFECTS OF VOLCANOES

Geothermal features Warm/hot springs, lakes, fumaroles, steaming vents

Taal Geysering Makiling Mud Pool

Taal Geysering Macban Geothermal Plant BENEFICIAL EFFECTS OF VOLCANOES

Good site for treking, camping, enjoying nature BENEFICIAL EFFECTS OF VOLCANOES

Eruptive activities Activities can be observed from safe areas

1965 eruption (Mt. Tabaro, Taal 1993 eruption Mayon Volcano Volcano)

2006 eruption Mayon Volcano BENEFICIAL EFFECTS OF VOLCANOES

Preserved Impacts of Historical Eruptions

Cabetican Church, buuried in lahar deposits after 1991 eruption, Pinatubo Volcano

Cagsawa Ruins, 1814 eruption, Mayon Volcano VOLCANOES AND TOURISM • The country has many volcanoes, active and inactive, which can be good sites for tourism

• Volcanoes are attractive travel destinations: beautiful sites because of its landforms/shapes; geothermal features; good site for trekking, camping, enjoying nature; preserved impacts of historical eruptions; eruptive activities observed from safe areas

• Safety should always be considered in developing and maintaining tourism in volcanic areas and in locating facilities

• The natural environment should be conserved and the well- being of the local people should be improved in developing volcanoes as travel destinations ( Respect local/cultural traditions and etiquette; practice minimum environmental impact ) Earthquake & Tsunami (24/7): Contact Us: Tel. Numbers http://www.phivolcs.dost.gov.ph • +632 929-9254

• +632 426-1468 loc 124 / 125 /phivolcs_dost Fax number

• +632 927-1087

Volcano (24/7): Tel. Numbers Philippine Institute of • +632 426-1468 loc 127 Volcanology and Telefax number Seismology (PHIVOLCS-DOST) • +632 927-1095

IEC materials: • +632 426-1468 loc 128 • +632 927-4524