M 4.03 - 3 km ENE of Alamo, CA
Saturday, September 6, 2008 at 04:00:15 UTCLocation: 37.9°N 122.0°W Depth: 16km
Alert version 4
Summary
Estimated Population Exposed to Earthquake Shaking
Est. Modified Mercalli Intensity | Est. Population Exposure (k = x1000) | Perceived Shaking | Potential Structure Damage | |
---|---|---|---|---|
Resistant | Vulnerable | |||
X | 0 | Extreme | V. Heavy | V. Heavy |
IX | 0 | Violent | Heavy | V. Heavy |
VIII | 0 | Severe | Moderate/Heavy | Heavy |
VII | 0 | Very Strong | Moderate | Moderate/Heavy |
VI | 0 | Strong | Light | Moderate |
V | 323k | Moderate | V. Light | Light |
IV | 1,123k | Light | None | None |
II-III | 5,756k* | Weak | None | None |
I | 2,458k* | Not Felt | None | None |
MMI | City | Population |
---|---|---|
V | Danville | 42k |
V | Alamo | 17k |
V | San Ramon | 44k |
V | Moraga | 16k |
V | Walnut Creek | 65k |
V | Diablo | 1k |
IV | Oakland | 399k |
III | San Francisco | 732k |
II | Stockton | 289k |
II | San Jose | 894k |
I | Sacramento | 467k |
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, the population in this region resides in structures that are resistant to earthquake shaking, though some vulnerable structures exist.
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/nc/shake/51207740.
Exposure
Est. Modified Mercalli Intensity | Est. Population Exposure (k = x1000) | Perceived Shaking | Potential Structure Damage | |
---|---|---|---|---|
Resistant | Vulnerable | |||
X | 0 | Extreme | V. Heavy | V. Heavy |
IX | 0 | Violent | Heavy | V. Heavy |
VIII | 0 | Severe | Moderate/Heavy | Heavy |
VII | 0 | Very Strong | Moderate | Moderate/Heavy |
VI | 0 | Strong | Light | Moderate |
V | 323k | Moderate | V. Light | Light |
IV | 1,123k | Light | None | None |
II-III | 5,756k* | Weak | None | None |
I | 2,458k* | Not Felt | None | None |
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
MMI | City | Population |
---|---|---|
V | Danville | 42k |
V | Alamo | 17k |
V | San Ramon | 44k |
V | Moraga | 16k |
V | Walnut Creek | 65k |
V | Diablo | 1k |
V | Waldon | 5k |
V | Pleasant Hill | 34k |
V | Lafayette | 24k |
IV | Orinda | 18k |
IV | Dublin | 38k |
IV | Concord | 125k |
IV | Pacheco | 3k |
IV | Fairview | 9k |
IV | Clayton | 11k |
IV | Castro Valley | 62k |
IV | Union City | 69k |
IV | Ashland | 23k |
IV | San Leandro | 79k |
IV | Oakland | 399k |
IV | Cherryland | 15k |
IV | Alameda | 70k |
III | Hayward | 140k |
III | Piedmont | 10k |
III | Bay Point | 21k |
III | Daly City | 98k |
III | Pittsburg | 62k |
III | Vine Hill | 3k |
III | South San Francisco | 58k |
III | Albany | 16k |
III | San Lorenzo | 23k |
III | Berkeley | 100k |
III | El Cerrito | 23k |
III | Fremont | 202k |
III | Brentwood | 46k |
III | Pleasanton | 66k |
III | Colma | 1k |
III | Kensington | 4k |
III | San Francisco | 732k |
III | Antioch | 106k |
III | Oakley | 26k |
III | Broadmoor | 4k |
III | Newark | 42k |
III | Union City | 66k |
III | Brisbane | 3k |
III | Mountain View | 2k |
III | East Richmond Heights | 3k |
III | Martinez | 36k |
III | Millbrae | 19k |
III | San Bruno | 39k |
III | Richmond | 103k |
III | Hercules | 23k |
III | Discovery Bay | 11k |
III | Pacifica | 36k |
III | Bethel Island | 2k |
III | El Sobrante | 13k |
III | Benicia | 26k |
III | Emeryville | 7k |
III | Sunol | 1k |
III | Pinole | 19k |
III | Rollingwood | 3k |
III | San Pablo | 31k |
III | Suisun City | 27k |
III | Hillsborough | 10k |
III | Rodeo | 9k |
III | Crockett | 3k |
III | Tara Hills | 5k |
III | Foster City | 28k |
III | Burlingame | 26k |
III | Rio Vista | 7k |
III | Sausalito | 7k |
III | Fairfield | 105k |
III | Livermore | 80k |
III | Montara | 3k |
III | San Mateo | 89k |
II | Moss Beach | 1k |
II | Mill Valley | 13k |
II | East Palo Alto | 32k |
II | Tracy | 83k |
II | San Carlos | 26k |
II | Corte Madera | 9k |
II | Strawberry | 5k |
II | El Granada | 6k |
II | Larkspur | 11k |
II | Vacaville | 96k |
II | Belvedere | 2k |
II | Redwood City | 71k |
II | Vallejo | 120k |
II | Kentfield | 6k |
II | Country Club | 9k |
II | Atherton | 6k |
II | Tiburon | 8k |
II | Ross | 2k |
II | Belmont | 23k |
II | Lincoln Village | 4k |
II | Palo Alto | 56k |
II | Stockton | 289k |
II | Lathrop | 13k |
II | French Camp | 4k |
II | San Anselmo | 11k |
II | Menlo Park | 29k |
II | Emerald Lake Hills | 4k |
II | August | 8k |
II | Kennedy | 3k |
II | Dixon | 16k |
II | Fairfax | 7k |
II | Woodacre | 1k |
II | Woodside | 5k |
II | Garden Acres | 10k |
II | American Canyon | 15k |
II | Morada | 3k |
II | Lexington Hills | 2k |
II | Green Valley | 1k |
II | Manteca | 65k |
II | Bolinas | 1k |
II | San Rafael | 55k |
II | Santa Clara | 102k |
II | Lodi | 62k |
II | Burbank | 5k |
II | Santa Venetia | 4k |
II | West Menlo Park | 3k |
II | Half Moon Bay | 12k |
II | Campbell | 36k |
II | Buena Vista | 1k |
II | Seven Trees | 1k |
II | Milpitas | 62k |
II | Winters | 6k |
II | San Jose | 894k |
II | Monte Sereno | 3k |
II | Sunnyvale | 126k |
II | Ripon | 13k |
II | Portola Valley | 4k |
II | Davis | 65k |
II | Stanford | 12k |
II | Grayson | 1k |
II | Napa | 77k |
II | Galt | 23k |
II | Linden | 1k |
II | Los Gatos | 27k |
II | Salida | 17k |
II | Ben Lomond | 2k |
II | Novato | 48k |
II | Cambrian Park | 3k |
II | Yountville | 3k |
II | Boulder Creek | 3k |
II | Lockeford | 3k |
II | Saratoga | 28k |
II | Laguna | 46k |
II | Cupertino | 50k |
II | Elk Grove | 94k |
II | Del Rio | 1k |
II | Riverdale Park | 1k |
II | Patterson | 15k |
II | Cottonwood | 3k |
I | West Sacramento | 41k |
I | Escalon | 7k |
I | Scotts Valley | 11k |
I | Loyola | 3k |
I | Sacramento | 467k |
I | Los Altos Hills | 8k |
I | Petaluma | 55k |
I | Esparto | 2k |
I | Woodland | 51k |
I | Los Altos | 26k |
I | Modesto | 216k |
I | Felton | 1k |
I | Alum Rock | 14k |
I | Florin | 29k |
I | Shackelford | 5k |
I | Bystrom | 4k |
I | East Foothills | 8k |
I | Wilton | 4k |
I | Eldridge | 1k |
I | Saint Helena | 6k |
I | La Riviera | 10k |
I | Ceres | 40k |
I | Day Valley | 4k |
I | Deer Park | 1k |
I | Rosemont | 23k |
I | Morgan Hill | 34k |
I | Empire | 4k |
I | Mountain View | 68k |
I | Riverbank | 18k |
I | Keyes | 5k |
I | San Martin | 6k |
I | Hughson | 6k |
I | Oakdale | 18k |
I | Newman | 8k |
I | Angwin | 3k |
I | Roseland | 5k |
I | Rancho Cordova | 59k |
I | Foothill Farms | 17k |
I | Inverness | 1k |
I | Carmichael | 50k |
I | Rohnert Park | 41k |
I | Rio Linda | 11k |
I | Bodega Bay | 1k |
I | Turlock | 67k |
I | Gold River | 8k |
I | Gustine | 5k |
I | Santa Rosa | 155k |
I | North Highlands | 45k |
I | Boyes Hot Springs | 7k |
I | Valley Springs | 2k |
I | Occidental | 1k |
I | Orangevale | 27k |
I | Plymouth | 1k |
I | Guerneville | 2k |
I | Forestville | 2k |
I | Jackson | 4k |
I | El Dorado Hills | 25k |
I | Graton | 2k |
I | Folsom | 67k |
I | Diamond Springs | 6k |
I | Healdsburg | 11k |
I | Monte Rio | 1k |
I | Cameron Park | 16k |
I | Deer Park | 1k |
I | Los Banos | 33k |
I | Delhi | 11k |
I | Sutter Creek | 2k |
I | Calistoga | 5k |
I | Shingle Springs | 3k |
I | Temelec | 1k |
I | Cotati | 6k |
I | Sonoma | 9k |
I | Windsor | 25k |
I | El Verano | 4k |
I | Sebastopol | 7k |
I | Denair | 3k |
I | Ione | 7k |
I | Waterford | 8k |
I | Rancho Murieta | 5k |
I | Rancho Calaveras | 4k |
I | Fair Oaks | 28k |
I | East Oakdale | 2k |
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.