Anthony J. Crone
Edwin Harp
Rex Baum
Jon J. Major
Carlos Pullinger
C.D. Escobar
Mauricio Martinez
Mark E. Smith
Randall W. Jibson
2004
<p><span>During a one-month period </span><span class="ScopusTermHighlight">in</span><span> early </span><span class="ScopusTermHighlight">2001</span><span>, </span><span class="ScopusTermHighlight">El</span><span> </span><span class="ScopusTermHighlight">Salvador</span><span> experienced two devastating </span><span class="ScopusTermHighlight">earthquakes</span><span>. On </span><span class="ScopusTermHighlight">13</span><span> </span><span class="ScopusTermHighlight">January</span><span>, a M-7.7 </span><span class="ScopusTermHighlight">earthquake</span><span> centered ∼40 km off the southern coast </span><span class="ScopusTermHighlight">in</span><span> the Pacific Ocean caused widespread damage and fatalities throughout much of the country. The </span><span class="ScopusTermHighlight">earthquake</span><span> </span><span class="ScopusTermHighlight">triggered</span><span> thousands of </span><span class="ScopusTermHighlight">landslides</span><span> that were broadly scattered across the southern half of the country. The most damaging </span><span class="ScopusTermHighlight">landslide</span><span>, a rapidly moving mass of ∼130, 000 m </span><sup>3</sup><span>, occurred </span><span class="ScopusTermHighlight">in</span><span> the Las Colinas neighborhood of Santa Tecla, where ∼585 people were killed. Another large </span><span class="ScopusTermHighlight">landslide</span><span> (∼750, 000 m </span><sup>3</sup><span>) near the city of San Vicente blocked the Pan-American Highway for several weeks. One month later, on </span><span class="ScopusTermHighlight">13</span><span> </span><span class="ScopusTermHighlight">February</span><span>, a M-6.6 </span><span class="ScopusTermHighlight">earthquake</span><span> occurred ∼40 km east-southeast of San </span><span class="ScopusTermHighlight">Salvador</span><span> and </span><span class="ScopusTermHighlight">triggered</span><span> additional thousands of </span><span class="ScopusTermHighlight">landslides</span><span> </span><span class="ScopusTermHighlight">in</span><span> the area east of Lake Ilopango. The </span><span class="ScopusTermHighlight">landslides</span><span> were concentrated </span><span class="ScopusTermHighlight">in</span><span> a 2500 km</span><sup>2</sup><span> area and were particularly abundant </span><span class="ScopusTermHighlight">in</span><span> areas underlain by thick deposits of poorly consolidated, late Pleistocene and Holocene Tierra Blanca rhyolitic tephras erupted from Ilopango caldera. Most of the </span><span class="ScopusTermHighlight">triggered</span><span> </span><span class="ScopusTermHighlight">landslides</span><span> were relatively small, shallow failures, but two large </span><span class="ScopusTermHighlight">landslides</span><span> occurred that blocked the </span><span class="ScopusTermHighlight">El</span><span> Desagüe River and the Jiboa River. The two </span><span class="ScopusTermHighlight">earthquakes</span><span> </span><span class="ScopusTermHighlight">triggered</span><span> similar types of </span><span class="ScopusTermHighlight">landslides</span><span>, but the distribution of </span><span class="ScopusTermHighlight">triggered</span><span> </span><span class="ScopusTermHighlight">landslides</span><span> differed because of different </span><span class="ScopusTermHighlight">earthquake</span><span> source parameters. The largemagnitude, deep, offshore </span><span class="ScopusTermHighlight">earthquake</span><span> </span><span class="ScopusTermHighlight">triggered</span><span> broadly scattered </span><span class="ScopusTermHighlight">landslides</span><span> over a large region, whereas the shallow, moderate-magnitude </span><span class="ScopusTermHighlight">earthquake</span><span> centered within the country </span><span class="ScopusTermHighlight">triggered</span><span> a much smaller, denser concentration of </span><span class="ScopusTermHighlight">landslides</span><span>. These results are significant </span><span class="ScopusTermHighlight">in</span><span> the context of seismic-hazard mitigation for various </span><span class="ScopusTermHighlight">earthquake</span><span> scenarios.</span></p>
application/pdf
10.1130/0-8137-2375-2.69
en
Geological Society of America
Landslides triggered by the 13 January and 13 February 2001 earthquakes in El Salvador
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