Landslides triggered by the 1994 Northridge, California, earthquake

Bulletin of the Seismological Society of America - Tập 86 Số 1B - Trang S319-S332 - 1996
Edwin L. Harp1, Randall W. Jibson1
1U.S. Geological Survey, Denver, Colorado, 80225

Tóm tắt

Abstract The 17 January 1994 Northridge, California, earthquake (Mw = 6.7) triggered more than 11,000 landslides over an area of about 10,000 km2. Most of the landslides were concentrated in a 1000-km2 area that included the Santa Susana Mountains and the mountains north of the Santa Clara River valley. We mapped landslides triggered by the earthquake in the field and from 1:60,000-nominal-scale aerial photography provided by the U.S. Air Force and taken the morning of the earthquake; these mapped landslides were subsequently digitized and plotted in a GIS-based format. Most of the triggered landslides were shallow (1- to 5-m thick), highly disrupted falls and slides within weakly cemented Tertiary to Pleistocene clastic sediment. Average volumes of these types of landslides were less than 1000 m3, but many had volumes exceeding 100,000 m3. The larger disrupted slides commonly had runout paths of more than 50 m, and a few traveled as far as 200 m from the bases of steep parent slopes. Deeper (>5-m thick) rotational slumps and block slides numbered in the tens to perhaps hundreds, a few of which exceeded 100,000 m3 in volume. Most of these were reactivations of previously existing landslides. The largest single landslide triggered by the earthquake was a rotational slump/block slide having a volume of 8 × 106 m3. Analysis of the mapped landslide distribution with respect to variations in (1) landslide susceptibility and (2) strong shaking recorded by hundreds of instruments will form the basis of a seismic landslide hazard analysis of the Los Angeles area.

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Tài liệu tham khảo

Barrows A. G. (1986). Landslide hazards in the east half of the Val Verde quadrangle, Los Angeles County, California, Calif. Dept. Cons., Div. Mines Geol. Open-File Rept. 86-9.

California Department of Health Services, Coccidioidomycosis or Valley Fever

Centers for Disease Control and Prevention, (1994), Emerging infectious diseases: Coccidioidomycosis following the Northridge earthquake, California, 1994, MMWR, 43, 194

Cloud, (1975), Strong motion data from the San Fernando, California, earthquake of February 9, 1971, San Fernando, California, Earthquake of 9 February 1971, 273

Harp, (1993), An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch Front, Bull. Assoc. Eng. Geol., 30, 293

Irvine P. J. (1989). Landslide hazards in the north half of the Calabasas quadrangle, Los Angeles and Ventura Counties, California, Calif. Dept. Cons., Div. Mines Geol.Open-File Rept. 89-18.

Jibson, (1994), Land-slides triggered by the 17 January 1994 Northridge, California, earthquake, Earthquakes Volcanoes, 25

Jibson, (1994), Landslides can be hazardous to your health: an outbreak of coccidioidomycosis (valley fever) caused by landslides triggered by the 1994 Northridge, California, earthquake (abstract), Geol. Soc. Am. Abs. Prog., 26, A

Keefer, (1984), Landslides caused by earthquakes, Geol. Soc. Am. Bull., 95, 406, 10.1130/0016-7606(1984)95<406:LCBE>2.0.CO;2

Shakal A. Huang M. Darragh R. Cao T. Sherburne R. Malhotra P. Cramer C. Sydnor R. Graizer V. Maldonado G. Peterson C. Wampole J. (1994). CSMIP strong-motion records from the Northridge, California, earthquake of 17 January 1994, Calif. Dept. Conserv., Div. Mines Geol., Report no. OSMS 94-07.

Wald D. J. Heaton T. H. (1994). A dislocation model of the 1994 Northridge, California, earthquake determined from strong ground motions, U.S. Geol. Surv.Open-File Rept. 94-278.

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Bulletin of the Seismological Society of America

Tập 86 Số 1B

S319-S332

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