You are here: Home » Earthquake Center » PAGER

M 4.87 - 33.6 miles SSE of Seldovia

Thursday, April 30, 2009 at 04:54:57 UTC
Location: 59.0°N 151.3°W  Depth: 53km
Alert version 5

Summary

[PDF]

Estimated Population Exposed to Earthquake Shaking

Est. Modified
Mercalli Intensity
Est. Population
Exposure (k = x1000)
Perceived ShakingPotential Structure Damage
ResistantVulnerable
X0ExtremeV. HeavyV. Heavy
IX0ViolentHeavyV. Heavy
VIII0SevereModerate/HeavyHeavy
VII0Very StrongModerateModerate/Heavy
VI0StrongLightModerate
V0ModerateV. LightLight
IV0LightNoneNone
II-III9k*WeakNoneNone
I0*Not FeltNoneNone
*Estimated exposure only includes population within the map area.

Population Exposure
 Population per ˜1 square km from Landscan 2005
Population Exposure
Selected City Exposure

MMICityPopulation
IIHomer6k
IIFritz Creek1k
IIDiamond Ridge1k
 
 
 
 
 
 
 
 
Shaking Intensity
    MMI
Shakemap

Overall, the population in this region resides in structures that are a mix of vulnerable and earthquake resistant construction. On March 28, 1964 (UTC), a magnitude 9.2 earthquake and tsunami occurred near the Prince William Sound, Alaska, region 304 km northeast of the location of this earthquake, with estimated population exposures of 24,000 at intensity VIII and 400,000 at intensity VII, resulting in an estimated 15 fatalities.


 

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

[Population | Shakemap]
Population Exposure

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.

Shakemap

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/ak/shake/102787.

Exposure

Est. Modified
Mercalli Intensity
Est. Population
Exposure (k = x1000)
Perceived ShakingPotential Structure Damage
ResistantVulnerable
X0ExtremeV. HeavyV. Heavy
IX0ViolentHeavyV. Heavy
VIII0SevereModerate/HeavyHeavy
VII0Very StrongModerateModerate/Heavy
VI0StrongLightModerate
V0ModerateV. LightLight
IV0LightNoneNone
II-III9k*WeakNoneNone
I0*Not FeltNoneNone
*Estimated exposure only includes population within the map area.

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

MMICityPopulation
IIHomer6k
IIFritz Creek1k
IIDiamond Ridge1k

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.


 

Details

Magnitude4.87
Max MMIIII
Date-TimeThursday, April 30, 2009 at 04:54:57 UTC
Location58.994°N, 151.312°W
Depth53.3 km (33.1 miles)
Event IDAK102787
Version5