M 4.7 - 16.3 mi SE of Calexico, CA

Summary

Population Exposure

 Population per ˜1 square km from Landscan 2005

Selected City Exposure

MMI	City	Population
V	Delta	5k
V	Puebla	8k
V	Mexicali	597k
V	Calexico	36k
V	Progreso	5k
IV	Guadalupe Victoria	18k
IV	Heber	3k
IV	El Centro	38k
III	San Luis Rio Colorado	139k
III	Yuma	84k
II	Fortuna Foothills	30k

Shaking Intensity

    MMI

Users should consider the preliminary nature of this information and check for updates as additional data becomes available. Population exposure estimates are NOT a direct estimate of earthquake damage; comparable shaking will result in significantly lower losses in regions with well built structures than in regions with vulnerable structures. Overall, structures in this region are a mix of vulnerable and resistant construction. A magnitude 8.0 earthquake struck the Michoacan, Mexico region on September 19, 1985 (UTC), with estimated population exposures of 82,000 at intensity VIII and 340,000 at intensity VII, resulting in 9,500 deaths. Recent earthquakes in this area have also triggered landslide hazards that have contributed to losses.

PAGER results are generally available on the Internet within 30 minutes of the earthquake's occurrence. However, information on the extent of shaking will be uncertain in the minutes and hours following an earthquake and typically improves as additional sensor data and reported intensities are acquired and incorporated into models of the earthquake's source. Users of PAGER exposure estimates should account for uncertainty and always seek the most current PAGER release for any earthquake.

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. The ground shaking estimates can be obtained from http://earthquake.usgs.gov/shakemap/ci/shake/14351300.

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.

Downloads

• 
  onePAGER PDF
  273 kB
• 
  Exposure XML
  13 kB
• 
  Shakemap
  26 kB
• 
  Population Map
  45 kB
• 
  Population PDF
  139 kB

Details