Metadata Identifier: gov.noaa.ngdc.mgg.photos:G01230

Aggregation Info | Bands | Citations | Constraints | Coverage Descriptions | Dimensions | Extents | Formats | Geographic Bounding Box
Georectified Information | Georeferenceable Information | Identifiers | Instruments | Mediums | OnlineResources | Operations
Platforms | Process Steps | Range Elements | Reference Systems | Responsible Parties | Series | Sources | Spatial Grids | Temporal Extents

MD_DataIdentification

Count Component Title Abstract
1 Mount Pinatubo Revisited; A Study of Lahar Erosion At dawn on June 15, 1991, a cataclysmic eruption began with a tremendous explosion that destroyed ten deserted villages. This eruption deposited approximately 5 to 7 km3 of volcanic fragments in pyroclastic flows on the slopes of the volcano and over neighboring towns and agricultural areas. It is this material that continues to threaten structures and lives in the area, in the form of lahars (debris flows) during heavy rainstorms. The lahars from the Mount Pinatubo volcano have been particularly damaging to the surrounding area. This set of slides shows how the disaster that began at Pinatubo in 1991 continues to threaten the population in the area. Mount Pinatubo is located on the Island of Luzon in the Philippines, about 100 km northwest of Manila. The volcano, with K-Ar datings of approximately 1.1 million years, and with the youngest carbon-14 dating of + 400 years B.P. (before present), is the youngest volcano in the western Luzon volcanic arc. On April 2, 1991, Pinatubo, which had been rumbling for months, stirred to life. Over the next six weeks earth tremors and minor explosions occurred. These natural warnings led to the evacuation of personnel at Clark Air Base and of 55,000 people in nearby towns and villages. At dawn on June 15, 1991, a cataclysmic eruption began with a tremendous explosion that destroyed ten deserted villages. The eruption deposited approximately 5 to 7 km3 of volcanic fragments in pyroclastic flows on the slopes of the volcano and over neighboring towns and agricultural areas. It is this material that continues to threaten structures and lives in the area, inthe form of lahars (debris flows) during heavy rainstorms. The Pinatubo deposits are subdivided into two general groups based on the lithology and age of emplacement: the "ancestral" and the "modern." The ancestral Pinatubo (+/- 1 million to +/-35,000 years B.P.) is an andesite-dacite stratovolcano of mostly laval flows and breccia deposits oflaharic origin. On its slopes are numerous elongated to sub-rounded hills made up of breccia, created mostly by the ancestral lahars. The modern Pinatubo (+/- 35,000 years to present) shows signs of repeated, very explosive eruptions which have produced large volumes of pumiceouspyroclastic flows. Pyroclastic flows, also known as nuee ardentes, or glowing avalanches, are extremely hot (+/-1,000 degrees Celsius), often incandescent, highly fluid, gravity-driven density currents of gas and volcanic fragments that sweep down slope and travel at hurricane speed (+/-100 km per hour). Pyroclastic flows are generated when the density of the rising column of volcanic fragments and gas exceeds that of the surrounding atmosphere. Gravity causes a portion or all of the column to collapse and flow down the flanks of the volcano. Most of the 1991 pyroclastic flow deposits were emplaced during the June 15 eruption. The pre-eruption magma temperature of Pinatubo was about 800 degrees Celsius and the temperature of the emplaced pyroclastic flow was on the order of 600 degrees Celsius. The deposits are non-welded, dry, and very loose. The accumulated thickness of the pyroclastic flows varies, depending on the proximity to the crater and the pre-eruption morphology. It reaches more than 200 meters along deep pre-eruption valleys. The pyroclastic flow deposits of 1991 affected eight major watersheds around the slopes of the volcano and radically altered the hydrological regimes, leading to unprecedented amounts of erosion and sediment delivery in the form of destructive lahars. Lahars predominantly occur during the rainy season in the monsoon period, which lasts from June until November. Long-duration and high-intensity rainfall, associated with the occurrence of strong typhoons, are responsible for the production of large-magnitude lahars. Other factors contributing to the rapid erosion of lahars are: failure of lahar dams, secondary explosions produced by rapid vertical and lateral erosion of the pyroclastic flow deposits, and stream and river capture bringing deposits into new drainage systems. The rapid erosion or removal of the pyroclastic flow deposits has been one of the major social and scientific concerns after the 1991 eruption ofthe Pinatubo Volcano. The lahars from Pinatubo have resulted in loss of lives and damage to properties in areas surrounding the volcano. About 500,000 persons were left homeless and indirect impacts such as flooding and isolation have affected more than 1.3 million people in 39 different towns and four large cities. About 1,000 km2 of prime agricultural lands are atrisk. Lahars will continue to be an important hazard on the lower slopes of Pinatubo for a number of years.
Top

SV_Identification

none found
Top

CI_Citation

Count Component Title Date Citation Identifier
1 Container Packet ID
    1 Getty Thesaurus of Geographic Names
      1 GCMD Data Center Keywords Global Change Master Directory (GCMD) Data Center Keywords
        2020-01-09
      1 GCMD Project Keywords Global Change Master Directory (GCMD) Project Keywords
        2020-01-09
      1 INFOTERRA Keyword Thesaurus
        1 Mount Pinatubo Revisited; A Study of Lahar Erosion
          1994
        Document
        1 NASA/GCMD Earth Science Keywords
          Top

          CI_Series

          none found
          Top

          CI_ResponsibleParty

          Count Component Individual Organization Position Email Role Linkage
          1 NCEI User Services (distributor) DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce User Services ngdc.info@noaa.gov distributor
          1 DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce (comp) originator
          2 GCMD Landing Page NASA Goddard Space Flight Center, Earth Science Data and Information System custodian https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords
          3 Hazards Data Manager (pointOfContact) NOAA National Centers for Environmental Information Hazards Data Manager haz.info@noaa.gov pointOfContact
          1 NCEI (publisher) NOAA National Centers for Environmental Information publisher
          1 Anna Milan NOAA National Centers for Environmental Information Metadata Specialist editor
          1 National Geophysical Data Center publisher
          Top

          CI_OnlineResource

          Count Component Linkage Name Description Function
          2 https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information
          1 https://www.ngdc.noaa.gov/hazard/
          1 https://www.ngdc.noaa.gov/hazardimages/
          Top

          MD_Identifier or RS_Identifier

          Count Component Code
          1 Document
          1 G01143
          Top

          EX_Extent

          Bounding Box Temporal Extent
          Count Component Description West East North South Start End
          1 120.21 120.21 15.08 15.08 1991-04-02 1993-10-06
          Top

          EX_GeographicBoundingBox

          Count Component West East North South
          1 120.21 120.21 15.08 15.08
          Top

          EX_TemporalExtent

          Count Component Start End
          1 1991-04-02 1993-10-06
          Top

          MD_Format

          Count Component Name Version specification
          1 TIFF
          Top

          MD_Medium

          Count Component Name mediumFormat mediumNote
          1 cdRom iso9660
          Top

          MD_Constraints

          Count Component Use Limitation
          Top

          MD_ReferenceSystem

          none found
          Top

          MD_GridSpatialRepresentation

          none found
          Top

          MD_Georeferenceable or MI_Georeferenceable

          none found
          Top

          MD_Georectified or MI_Georectified

          none found
          Top

          MD_Dimension

          none found
          Top

          MD_CoverageDescription or MI_CoverageDescription

          none found
          Top

          MD_Band or MI_Band

          none found
          Top

          MI_RangeElementDescription

          none found
          Top

          MD_AggregateInformation

          Count Component Title Code Association Type Code
          1 G01143 largerWorkCitation
          Top

          LE_Source or LI_Source

          none found
          Top

          LE_ProcessStep or LI_ProcessStep

          Count Component DateTime Description
          1 2015-04-22T00:00:00 NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
          Top

          MI_Operation

          none found
          Top

          MI_Platform

          none found
          Top

          MI_Instrument

          none found
          Top