Geology and Remote Sensing Mt Pinatubo and Taal Volcanoes PowerPoint Presentation

Slide 1 -

Geology and Remote Sensing of Mt. Pinatubo & Taal Volcanoes, the Philippines Peter Mouginis-Mark University of Hawaii pmm@pgd.hawaii.edu Work funded by NASA’s Solid Earth and Natural Hazards Program

Slide 2 -

LOCATION OF VOLCANOES IN THE PHILIPPINES

Slide 3 -

ppt slide no 3 content not found

Slide 4 -

Landsat 7 coverage (obtained over 3 different days)

Slide 5 -

Mt. PINATUBO ERUPTIONS June 1991

Slide 6 -

Prior to eruption

Slide 7 -

Fumaroles on flanks, April 1991

Slide 8 -

June 12th, 1991 eruption

Slide 9 -

Giant pyroclastic flows, June 15th 1991 form off of collapsing eruption column

Slide 10 -

The view from space via the Japanese GMS-5 geostationary satellite

Slide 11 -

Early effects on the ground

Slide 12 -

Sediment-laden rivers destroy roads & bridges

Slide 13 -

Major landscape changes: Pyroclastic flows in-filled pre-existing river valleys (the peaks in two views below are the same feature)

Slide 14 -

AIR PHOTOS

Slide 15 -

Summit caldera of Mt. Pinatubo, Nov. 1999. The low-point in the rim is a future hazard as the lake will eventually over-top here.

Slide 16 -

Typical view of eastern flank, Nov. 1999

Slide 17 -

Erosion of ignimbrite fan on NW. flank, November 1999

Slide 18 -

Erosion of river valley on the northern flank, Nov. 1999

Slide 19 -

Sediment fills valley floor downslope on lower E. flank November 1999

Slide 20 -

Detail of lahar-filled valley E. flank, Nov. 1999

Slide 21 -

GROUND PHOTOS

Slide 22 -

Exploring eroded valley, SW flank Nov. 1999

Slide 23 -

Crossing the sediment-laden streams is a real challenge! So much sediment is in these streams that they easily knock you over.

Slide 24 -

Valley erosion can be extreme in places: Up to 20 m down-cutting during one typhoon! This mosaic shows the remains of the 1991 deposit (white unit) that has been cut by younger flash floods

Slide 25 -

Erosion within the 1991 deposit

Slide 26 -

Erosion of 1991 deposit

Slide 27 -

Amazing landscapes!

Slide 28 -

Vegetation is starting to grow back on western fan. Summit of Mt. Pinatubo in background

Slide 29 -

“LAHARS” (MUDFLOWS) AND THE RESULTANT DAMAGE

Slide 30 -

Major changes in valley floor elevation after single lahar has formed after typhoon.

Slide 31 -

The impact on villages within the path of a lahar can be extreme

Slide 32 -

While old houses are buried, new homes are built on stilts to try to avoid the next lahar

Slide 33 -

An old church has been partially-buried so that you now enter on the 2nd floor. Ronnie Torres shows the church prior to the lahars.

Slide 34 -

Giant dikes made from old lahar and covered with concrete now try to protect areas from new lahars

Slide 35 -

The contrast between areas protected by the dikes and unprotected is striking -- and it’s all an issue of insurance for redevelopment!

Slide 36 -

Some homes, once buried by lahar, and now being exposed by recent erosion

Slide 37 -

REMOTE SENSING DATA

Slide 38 -

Landsat 7 Path 116 Row 50

Slide 39 -

RADARSAT radar backscatter image of Mt. Pinatubo, February 1998

Slide 40 -

SPOT image of Mt. Pinatubo December 1991

Slide 41 -

RADARSAT radar backscatter image of western fan of Mt. Pinatubo

Slide 42 -

Clark Air Base: RADARSAT standard beam data set (25 m/pixel)

Slide 43 -

SPOT data of Mt. Pinatubo summit area soon after the eruption

Slide 44 -

Comparison of NW Summit from SPOT data obtained between 1991 and 1998 Red shows vegetation, the ash deposits are light blue Summit is at lower right

Slide 45 -

Changes in Mt. Pinatubo lahar deposits. Lower Pasig-Potrero River 1991 - 1996

Slide 46 -

ERS-1 radar backscatter image of Pasig-Potrero River showing low-backscatter lahar deposits

Slide 47 -

Shaded relief image of lahar fans SE of Mt. Pinatubo summit from NASA TOPSAR topographic data

Slide 48 -

Nighttime Landsat 7 thermal data of Mt. Pinatubo shows warm streams

Slide 49 -

TAAL VOLCANO (just south of Manila)

Slide 50 -

ppt slide no 50 content not found

Slide 51 -

RADARSAT scansar beam 1 (50 m/pixel) image of Taal Volcano and surrounding area

Slide 52 -

Space Shuttle radar (SIR-C/X-SAR) multi-wavelength (3, 5.6 and 24 cm) image of northern part of Taal Volcano

Slide 53 -

View of Lake Taal and Volcano Island from north rim, Nov. 1999

Slide 54 -

NW corner of Lake Taal

Slide 55 -

Over 4,000 people live without permission on the shores of Volcano Island

Slide 56 -

In the event of an eruption of Taal, all the population would have to leave Volcano Island via small boats

Slide 57 -

View of the volcanic lake in middle of Volcano Island (middle of Lake Taal)

Slide 58 -

In Fall 1999, this vent on Volcano Island was actively geysering. It was quiet in November 1999.

Slide 59 -

Close-up view of recently active vent on Volcano Island, in the middle of Taal Volcano

Slide 60 -

Even around the rim of Lake Taal, people and their fish farms are at risk from tsunamis generated by eruptions.