M 4.5 - 0.5 mi W of San Bernardino, CA

Summary

Population Exposure

 Population per ˜1 square km from Landscan 2005

Selected City Exposure

MMI	City	Population
V	San Bernardino	202k
V	Colton	52k
V	Grand Terrace	12k
V	Highgrove	3k
V	Bloomington	22k
V	Highland	51k
V	Muscoy	9k
III	Los Angeles	3694k
III	Anaheim	328k
III	Santa Ana	343k
II	Long Beach	482k

Shaking Intensity

    MMI

Overall, the population in this region resides in structures that are resistant to earthquake shaking, though some vulnerable structures exist. A magnitude 5.6 earthquake occurred near the Sierra Madre, California, region 67 km west of the location of this earthquake on June 28, 1991 (UTC), with estimated population exposures of 1,267,000 at intensity VI and 12,587,000 at intensity V, resulting in an estimated 1 fatality. On February 9, 1971 (UTC), a magnitude 6.6 earthquake occurred near the San Fernando, California, region 106 km west of the location of this earthquake, with estimated population exposures of 21,000 at intensity IX or greater and 319,000 at intensity VIII, resulting in an estimated 65 fatalities. Recent earthquakes in this area have caused, landslides and liquefaction that may 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/10370141.

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
  332 kB
• 
  Exposure XML
  88 kB
• 
  Shakemap
  35 kB
• 
  Population Map
  62 kB
• 
  Population PDF
  210 kB

Details