Earthquake report

The following appeared on TAXACOM and is reposted here with permission.

    Date: 20 Jan 94
    From: Robert Lavenberg <rlavenbe [at] bcf__usc__edu>
    Subject: Natural History Museum & Earthquake
    To: Multiple recipients of list TAXACOM
        <TAXACOM [at] HARVARDA__HARVARD__EDU>

    Status of the collections and condition of the Natural History
    Museum of Los Angeles County (LACM) as a result of the earthquake of
    January 17, 1994.

    The Natural History Museum of Los Angeles County suffered little
    collection damage resulting from the earthquake, but the building
    sustained some damage in the form of cracked walls throughout.
    Damage to the building and offices was more prevalent on the upper
    floors (third and fourth floors).  On the ground floor no collection
    damage occurred in holdings for ichthyology, herpetology,
    polycheates, crustacea-echinoderms, archeology-anthropology, or the
    molecular laboratory.  Most of these collections are maintained in
    Spacesaver compactors, and these installations served the
    collections well.  Many bottles were knocked down, but none broke
    and none were thrown from the carriages.  The tectonic braces served
    the carriages well. Further, no damaged occurred in any of the
    ground floor offices. The first floor serves for exhibits only, and
    no significant damaged occurred; some items in the various exhibits
    fell over or were displaced. Little damaged occurred.  Second floor
    serves exhibits, administrative offices, and collections, no damaged
    occurred in ornithology-mammalogy, but a few items were broken in
    the archeology-anthropology storerooms.  Some building damaged was
    noted between the administrative offices complex as they attached to
    the main building.  The third floor serves for offices, and the
    malacological, some echinoderm, entomological, botanical, and some
    historical collections.  Little collection damaged occurred, but
    many of the offices were trashed.  The fourth floor serves for
    exhibition and paleontological offices; paleontological collections
    are also stored on the fourth floor. Although the heavy
    paleontological cases moved 6-7 inches, no collection damaged was
    noted; however, the exhibits areas suffered moderate damage.  Some
    wall cabinets ripped from the wall on both the third and fourth
    floors.  Again, some fourth floor offices were trashed like those on
    the third floor.

    The old 1913 domed-building apparently suffered little damaged. Data
    for the earthquake follows.

    The San Fernando Valley Earthquake of January 17, 1994 of magnitude
    6.6. Data prepared as of 7:30 am, January 17, 1994.

    An earthquake struck the San Fernando Valley this morning at 4:30 am
    Pacific Standard Time.  As of 7:00 am, 15 aftershocks of magnitude
    3.0 or larger have been recorded by the Southern California
    Seismographic Network.  The epicenter is located at 34! 13' north,
    118! 33' west at a depth of 14.6 kilometers.  The surface wave
    magnitude from the National Earthquake Information Center is 6.6.
    The local magnitude is 6.4.

    The focal mechanism of the earthquake shows almost pure thrust (rake
    of 80!) on a fault striking 15! west of north with a dip to the
    north of 30!.  The location of the mainshock's epicenter is located
    several kilometers south of the southern end of the rupture zone.
    Most of the aftershocks are located to the north of the mainshock
    around 10 kilometers depth.  At this point we have two competing
    hypothesis.  If the mainshock is on the north dipping place plane,
    it could be on the Elysian Park fold and thrust belt that produced
    the Whittier Narrows earthquake (magnitude 5.9) in 1987.  The
    aftershocks are then occurring because of sympathetic rerupturing of
    the 1971 zone.  The other possibility is that the mainshock occurred
    on the south dipping plane that is perhaps a backthrust of the main
    Elysian Park fault.

    R. Lavenberg
    Natural History Museum, Research and Collections
    Section of Vertebrates
    Voice 213 744-3446
    FAX 213 748-4432
    jim

Jim Croft
Herbarium CBG
Australian National Botanic Gardens
GPO Box 1777, Canberra, ACT 2601, AUSTRALIA
+61-6-2509 490
fax:  +61-6-2509 599
URL=http://155.187.10.12:80/people/croft.jim.html
Biodiversity Directorate
Australian Nature Conservation Agency

                                  ***
                  Conservation DistList Instance 7:52
                 Distributed: Friday, January 21, 1994
                        Message Id: cdl-7-52-005
                                  ***