ISO Table View Back to Collection NOAA/NESDIS/NGDC/MGG/Hazard_Photos
View Metadata As: Get Data, FAQ, HTML, 19139 XML
Assess Metadata For: Completeness, DOI Readiness, CSW Readiness, Components

Metadata Identifier: gov.noaa.ngdc.mgg.photos:G01196

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 Earthquake Damage in Mexico City, Mexico, September 19, 1985 On September 19, 1985, a magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 km2 area of Mexico City, 350 km from the epicenter. The underlying geology and geologic history of Mexico City contributed to this unusual concentration of damage at a distance from the epicenter. Of a population of 18 million, an estimated 10,000 people were killed, and 50,000 were injured. In addition, 250,000 people lost their homes and property damage amounted to $5 billion. This set of slides shows different types of damaged buildings and the major kinds of structural failure that occurred in this earthquake including collapse of top, middle and bottom floors and total building failure. The effect of the subsoils on the earthshaking and building damage are emphasized. Over 800 buildings crumbled, including hotels, hospitals, schools, and businesses. Communications between Mexico City and the outside world were interrupted for many days. Surrounding areas affected by the earthquake included the Mexican States of Jalisco, Guerrero, and Michoacan. Damage in the epicentral area wasrestricted to a few tourist resorts and industrial estates along the Mexico Pacific coast. A two-meter tsunami also caused some damage in this area. There are geologic reasons why Mexico and especially Mexico City are vulnerable to earthquake damage. Along the west coast of southern Mexico and Central America, the Cocos Plate dips beneath the North American Plate producing a very active seismic zone. Since the beginning of the Twentieth Century, 84 earthquakes of magnitude greater than 7.0 have occurred in this zone. The location of the 1985 earthquake's epicenter near the coast at the border between the states of Michoacan and Guerrero was not a surprise. Prior to the 1985 earthquake this area, located between two areas that had experienced recent earthquakes, was known as the "Michoacan Gap." The "gap" was filled in 1985 by the main shock and a severe aftershock (magnitude 7.5) that occurred two days later, on September 21. Mexico City lies in a broad basin formed approximately 30 million years ago by faulting of an uplifted plateau. Volcanic activity closed the basin and resulted in the formation of Lake Texcoco. The Aztecs chose an island in this lake as an easily defended location for their capitol. The expansion of Mexico City and the gradual draining of the lake left the world's largest population center located on unconsolidated lake-bed sediments. These soft sedimentary clay deposits amplified the seismic waves, or they liquefied, destroying the foundation of some buildings. Double resonance coupling between the earthquake waves, the subsoils, and the buildings caused intensity IX shaking in some areas, lasting up to three minutes. Earthquakes in 1957 and in 1979 also damaged Mexico City. However, neither of these earthquakes was quite as devastating as the 1985 earthquake. In the area of greatest damage in downtown Mexico City, some types of structures failed more frequently than others. In the highest damage category were buildings with six or more floors. Resonance frequencies of these buildings were similar to the resonance frequencies of the subsoil. Because of the unusual flexibility of Mexico City structures, upper floors swayed as much as one meter and frequently collapsed. Differential movements of adjacent buildings also resulted in damage. A flexible building often failed if it was held by adjacent, more rigid lower buildings. Damage or failure often occurred where two swaying buildings came in contact with each other. Corner buildings were also vulnerable to damage. Lessons learned from the patterns of earthquake damage need to be applied to prevent another disaster when an earthquake releases stress that is building in another area-along the Mexico coast between Acapulco and Zihuatanejo.
Top

SV_Identification

none found
Top

CI_Citation

Count Component Title Date Citation Identifier
1 Earthquake Damage in Mexico City, Mexico, September 19, 1985
    1994
Document
1 Getty Thesaurus of Geographic Names
    1 INFOTERRA Keyword Thesaurus
      1 GCMD Data Center Keywords NASA/GCMD Data Center Keywords
        2015-03-01
        1995-04-24
      1 NASA/GCMD Earth Science Keywords
        1 GCMD Project Keywords NASA/GCMD Project Keywords
          2015-03-01
          1995-04-24
        Top

        CI_Series

        none found
        Top

        CI_ResponsibleParty

        Count Component Individual Organization Position Email Role Linkage
        2 GCMD Valids http://gcmd.nasa.gov/learn/keyword_list.html
        1 Anna Milan Anna Milan DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce Metadata Specialist Anna.Milan@noaa.gov pointOfContact
        1 NCEI (publisher) DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce publisher
        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
        3 Hazards Data Manager (pointOfContact) DOC/NOAA/NESDIS/NCEI> National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce Hazards Data Manager haz.info@noaa.gov pointOfContact
        1 DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce (comp) originator
        2 GCMD User Support Office NASA GCMD User Support Office gcmduso@gcmd.gsfc.nasa.gov publisher http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso
        1 National Geophysical Data Center publisher
        Top

        CI_OnlineResource

        Count Component Linkage Name Description Function
        2 http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso GCMD Feedback Form Have a Comment for the GCMD? information
        2 http://gcmd.nasa.gov/learn/keyword_list.html GCMD's Science Keywords and Associated Directory Keywords This page describes the NASA GCMD Keywords, how to reference those keywords and provides download instructions. information
        1 http://www.ngdc.noaa.gov/hazard/
        1 http://www.ngdc.noaa.gov/hazardimages/event/show/13
        Top

        MD_Identifier or RS_Identifier

        Count Component Code
        1 Document
        Top

        EX_Extent

        Bounding Box Temporal Extent
        Count Component Description West East North South Start End
        1 -99.09 -99.09 19.24 19.24 1985-09-19 1985-09-21
        Top

        EX_GeographicBoundingBox

        Count Component West East North South
        1 -99.09 -99.09 19.24 19.24
        Top

        EX_TemporalExtent

        Count Component Start End
        1 1985-09-19 1985-09-21
        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

        none found
        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