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Jamison Steidl

Publications and source records attributed to Jamison Steidl.

3 recordsLinked to original sources
USGS2017

U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22

The mission of the National Strong-Motion Project is to provide measurements of how the ground and built environment behave during earthquake shaking to the earthquake engineering community, the scientific community, emergency managers, public agencies, industry, media, and other users for the following purposes: Improving engineering evaluations and design methods for facilities and systems; Providing timely information for earthquake early warning, damage assessment, and emergency response action; and Contributing to a greater understanding of the mechanics of earthquake rupture, groundmotion characteristics, and earthquake effects.

Open-File Report↗
USGS1996

The Loma Prieta, California, Earthquake of October 17, 1989: Main shock characteristics

The October 17, 1989, Loma Prieta, Calif., earthquake (0004:15.2 G.m.t. October 18; lat 37.036º N., long 121.883º W.; 19-km depth) had a local magnitude (M L ) of about 6.7, a surface-wave magnitude (M S ) of 7.1, a seismic moment of 2.2x10 19 N-m to 3.5x10 19 N-m, a source duration of 6 to 15 s, and an average stress drop of at least 50 bars. Slip occurred on a dipping fault surface about 35 km long and was largely confined to a depth of about 7 to 20 km. The slip vector had a large vertical component, and slip was distributed in two main regions situated northwest and southeast of the hypocenter. This slip distribution caused about half of the earthquake's energy to be focused toward the urbanized San Francisco Bay region, while the other half was focused toward the southeast. Had the rupture initiated at the southeast end of the aftershock zone, shaking in the bay region would have been both longer and stronger. These source parameters suggest that the earthquake was not a typical shallow San Andreas-type event but a deeper event on a different fault with a recurrence interval of many hundreds of years. Therefore, the potential for a damaging shallow event on the San Andreas fault in the Santa Cruz Mountains may still exist.

California↗