San Francisco Bay region landslide folio part D - Index to detailed maps of landslides in the San Francisco Bay region, California
A table keyed to 171 topographic quadrangles on a new
1:275,000-scale shaded-relief map speeds access to information on
landslide locations in the ten-county San Francisco Bay region.
Detailed maps showing individual landslides in nearly any area of
interest can be found quickly by knowing only the name of the
appropriate 7.5' quadrangle. The some-80 technical reports that
contain these maps may be consulted in the U.S. Geological Survey's
Menlo Park library collection.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest unknown
Ordinates (y-coordinates) are specified to the nearest unknown
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1927.
The ellipsoid used is Clarke 1866.
The semi-major axis of the ellipsoid used is 6378206.
The flattening of the ellipsoid used is 1/294.98.
It is often necessary to find out whether a landslide exists at a
particular Bay Area locale. Homeowners, landscape architects, real
estate developers, city planners, building officials,
emergency-response personnel, civil engineers, utilities workers,
and others all have occasion to know where the landslides are.
Because existing old and ancient landslides may be reactivated by
severe winter storms (Nilsen and others, 1976), timely availability
of information on landslide location can reduce losses of life and
property to the region's expanding population (San Francisco Bay
Landslide Mapping Team, 1997). This report enables visitors to the
USGS Menlo Park library to quickly find the detailed landslide map
they need. Access to the proper documents is achieved through a
table keyed to standard USGS 7.5' quadrangles‹a proxy for a true
index map, plus the library location of each document.
This report is preliminary and has not been reviewed for conformity
with U.S. Geological Survey editorial standards or with the North
American Stratigraphic Code. Any use of trade, product, or firm names
is for descriptive purposes only and does not imply endorsement by the
This database, identified as "Index to Detailed Maps of Landslides in
the San Francisco Bay Region, California," has been approved for
release and publication by the Director of the USGS. Although this
database has been subjected to rigorous review and is substantially
complete, the USGS reserves the right to revise the data pursuant to
further analysis and review. Furthermore, it is released on condition
that neither the USGS nor the United States Government may be held
liable for any damages resulting from its authorized or unauthorized