IMAGES FROM THE LOS ANGELES REGION SEISMIC EXPERIMENT

Below are a series of photos illustrating the types of instruments that were used, how the instruments were deployed, and the nature of the activities at the "LARSE headquarters" in a Glendora Warehouse.

(Photos provided by Michael Forrest)


LARSE "HEADQUARTERS"

In order to coordinate the field activities of the various phases of the LARSE, a central hub site was set up in a Glendora Warehouse. Instruments were picked up, deployed and returned to this location, where the data was then downloaded to computers and tapes.

Principal Investigator Gary Fuis (U.S. Geological Survey, Menlo Park) explains the LARSE to volunteers from local colleges.

Principal Investigator David Okaya (USC and SCEC)
organizing activities at the Glendora facility.

SGR instruments from Stanford University are prepared for deployment
by Michelle Robertson (USC) and Janice Murphy (USGS).

REFTEK instruments and seismometers are checked in at the Glendora facility.

Aaron Martin (UC Santa Barbara) supervises the downloading of data.

TYPES of INSTRUMENTS DEPLOYED

The blue box holds a Canadian EDA instrument; the tops of three seismometers (shown below) are visible in the box to the right.

This metal cylinder houses a three-component seismometer
used with the Canadian EDA instruments.

These orange geophones were another type of "seismometer" hooked up to
recording instruments such as the SGR's (shown below). At times it could be quite challenging to untangle the cables as Michael Forrest (USC)
is demonstrating here.

These SGR's from Stanford University, were yet another type of instrument
deployed to record the arrival of seismic waves from the land explosions.
These instruments record the data to a internal tape.

External GPS (Global Positioning Satellite) clocks were
hooked up to REFTEK recording devices in order to keep
accurate times for determining the arrivals of seismic
waves at the recording stations.

Hundreds of batteries were required to provide power to the instruments
deployed out in the field. (Sergio Chavez (University of Nevada
at Reno) makes sure that the batteries are recharged)

DEPLOYING INSTRUMENTS

Alan Walter deploys a REFTEK instrument at the Seal Beach Weapons station. An external GPS, a REFTEK, and a battery are evident. The buried cable and seismometer lie to the right of his feet. Nuclear weapons are stored in the bunker behind him.

Many instruments had to be hand carried into sites not accessible to vehicles.
Here instruments are being packed into the Vincent Gap in the San Gabriel
Mountains. The blue instrument is an EDA, the white one is an SGR.

Installing a REFTEK in the San Gabriel Mountains. These stations were camouflaged and often buried. Occasionally they were so well hidden that they were later quite difficult to find again.

OFFSHORE AND ONSHORE EXPLOSIONS

A number of artificial "seismic wave" sources were generated as part of the LARSE experiment. During the marine portion of the experiment, source shots were supplied by the R/V Ewing from Lamont-Doherty Earth Observatory at Columbia University.

A view of the R/V Ewing showing the 8000+ cubic inch airgun sources mounted on the back of the ship. Individual airgun busts from these sources could be seen at stations 200 km away.

During the land portion of LARSE, 63 explosions were set off at various locations along a line extending from Seal Beach over the San Gabriel Mountains and into the Mojave Desert at Harper Lake.

A "pre-explosion" shot casing.

A "post-explosion" shot casing.

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