Green Earthquake alert in Chile

USGS Prompt Assessment of Global Earthquakes for Response (version 2)

Summary

Overall, the population in this region resides in structures that are vulnerable to earthquake shaking, though some resistant structures exist. A magnitude 6.5 earthquake 382 km Northeast of this one struck Chile on March 17, 1985 (UTC), with estimated population exposures of 19,000 at intensity VIII and 47,000 at intensity VII, resulting in a reported 1 fatality. On March 3, 1985 (UTC), a magnitude 7.9 earthquake 336 km Northeast of this one struck Valparaiso, Chile, with estimated population exposures of 5,449,000 at intensity VII and 2,647,000 at intensity VI, resulting in a reported 177 fatalities. Recent earthquakes in this area have caused landslides and liquefaction that may have contributed to losses.

Version 2, released at 2010-03-16T17:22:07Z

Maps

Map of MMI contours plotted over population per ˜1 square km (see gray scale bar on top of map). The regions of integer MMI values are separated by the thick contour lines and labeled with Roman numerals. The total population exposure to a given MMI value is obtained by summing the population between the thick contour lines. This total is shown in population exposure table.

Map of shaking intensity. This map shows the estimated MMI as a continuous color scale.

Exposure

Table showing population exposed to different estimated Modified Mercalli Intensity (MMI) levels and the possible damage at different intensity levels for resistant and vulnerable structures. MMI describes the severity of an earthquake in terms of its effect on humans and structures and is a rough measure of the amount of shaking at a given location. Unlike earthquake magnitude, intensity varies with distance from the fault, and is influenced by the depth of the earthquake and the types of soils in the shaken region. Population outside the map bounds are not included in the totals.

Cities

Table of MMI estimates and populations for settlements falling within the map boundaries. The settlement name, location, and population are obtained from the freely-available GeoNames geographical database.

The information on this page is provided by the United States Geological Survey National Earthquake Information Centre. Refer to the PAGER web site for more information.