Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Unidentified earthquake damage image.

Earthquake damage

Earthquake damage

Olive View Hospital. San Fernando Valley Earthquake, California 1971.

Graphic of earthquake epicenter and damage to man-made structures.

Graphic of earthquake epicenter and damage to man-made structures.

Graphic of interior structure of Earth showing crust, mantle, core, and inner core.

Graphic of methodology to determine earthquake epicenter by using arc distances determined by analysis of seismograms

Graphic of raypaths of earthquake waves propagated through the Earth

Earthquake waves recorded on typical seismogram and paths of propagation through the Earth.

Graphic of tsunami warning system which was implemented and operated by the Coast and Geodetic Survey

World-wide network of standard seismograph stations managed by Coast and Geodetic Survey

Appears to be map of sunspot activity. Perhaps related to geomagnetic work.

Map of Earthquakes of the United States through 1963. Compiled by the Coast and Geodetic Survey

Map of Earthquakes 1966. Note correlation of oceanic earthquakes with mid-ocean ridge system.

Equipment at Coast and Geodetic Survey geophysical observatory

Equipment at Coast and Geodetic Survey geophysical observatory

Siesmograph equipment at Coast and Geodetic Survey geophysical observatory

Equipment at Coast and Geodetic Survey geophysical observatory

Portable seismological equipment

Coast and Geodetic Survey seismologist communicating with colleague

Coast and Geodetic Survey seismologist communicating with colleague

Coast and Geodetic Survey seismologist plotting earthquake epicenter with spacing dividers

Coast and Geodetic Survey seismologist plotting earthquake epicenter

Coast and Geodetic Survey seismologist obtaining data to plot earthquake epicenter

Coast and Geodetic Survey seismologists at work

Lieutenant Philip Taetz at desk. Possibly Honolulu Observatory.

Benioff horizontal seismometer

Benioff horizontal seismometer

Seismograph - spgr.

Seismograph - spgr.

Diagram of a type of seismometer

World Wide Standardized Seismological Network Galvos

World Wide Standardized Seismological Network Galvos

World Wide Standardized Seismological Network Galvos

Structure of Coast and Geodetic Survey Office of Seismology and Geomagnetism

What the Geomagnetism Branch of the Coast and Geodetic Survey did

Products of the Coast and Geodetic Survey Geomagnetism Program

An artist's conception of the Earth's structure and geomagnetic field

Geomagnetic observatories that were currently putting hourly values in machine- readable form as of 1969.

Geomagnetic observatories that were putting hourly values in machine-readable form prior to the International Geophysical Year.

Geomagnetic observatories with digital magnetometers as of 1969.

Geogmagnetic observatories that have facilities for semi-automatic scaling of magnetogram records as of 1969.