M 5.4 - 11 km E of Milpitas, CA
Wednesday, October 31, 2007 at 03:04:54 UTCLocation: 37.4°N 121.8°W Depth: 9km
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 | 441k | Strong | Light | Moderate |
V | 983k | Moderate | V. Light | Light |
IV | 1,955k | Light | None | None |
II-III | 4,679k* | Weak | None | None |
I | 0* | Not Felt | None | None |
MMI | City | Population |
---|---|---|
VI | East Foothills | 8k |
VI | San Jose | 894k |
VI | Burbank | 5k |
VI | Buena Vista | 1k |
V | Santa Clara | 102k |
V | Alum Rock | 14k |
V | Seven Trees | 1k |
IV | Modesto | 216k |
III | San Francisco | 732k |
III | Stockton | 289k |
III | Oakland | 399k |
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 designed to be resistant to earthquake shaking, though some vulnerable construction exists. A magnitude 6.7 earthquake struck the Northridge, California region on January 17, 1994 (UTC), with estimated population exposures of 110,000 at intensity IX or greater and 1.7 million at intensity VIII, resulting in 60 deaths. Recent earthquakes in this area have also triggered landslide and liquefaction 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/.
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 | 441k | Strong | Light | Moderate |
V | 983k | Moderate | V. Light | Light |
IV | 1,955k | Light | None | None |
II-III | 4,679k* | Weak | None | None |
I | 0* | 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 |
---|---|---|
VI | East Foothills | 8k |
VI | San Jose | 894k |
VI | Burbank | 5k |
VI | Buena Vista | 1k |
V | Santa Clara | 102k |
V | Alum Rock | 14k |
V | Seven Trees | 1k |
V | Milpitas | 62k |
V | Campbell | 36k |
V | Cambrian Park | 3k |
V | Sunol | 1k |
V | Sunnyvale | 126k |
V | Hollister | 37k |
IV | Lexington Hills | 2k |
IV | Los Gatos | 27k |
IV | Cupertino | 50k |
IV | Monte Sereno | 3k |
IV | Fremont | 202k |
IV | Morgan Hill | 34k |
IV | Gilroy | 45k |
IV | Newark | 42k |
IV | San Martin | 6k |
IV | Scotts Valley | 11k |
IV | Ben Lomond | 2k |
IV | Felton | 1k |
IV | Half Moon Bay | 12k |
IV | Boulder Creek | 3k |
IV | Ridgemark | 2k |
IV | Aptos | 9k |
IV | Day Valley | 4k |
IV | Dublin | 38k |
IV | Saratoga | 28k |
IV | Mountain View | 68k |
IV | Portola Valley | 4k |
IV | Santa Cruz | 54k |
IV | Loyola | 3k |
IV | San Juan Bautista | 1k |
IV | Pleasanton | 66k |
IV | Live Oak | 17k |
IV | Aromas | 3k |
IV | Los Altos | 26k |
IV | Freedom | 5k |
IV | Rio Del Mar | 9k |
IV | Amesti | 2k |
IV | Interlaken | 7k |
IV | Los Altos Hills | 8k |
IV | Soquel | 5k |
IV | Corralitos | 2k |
IV | East Palo Alto | 32k |
IV | Watsonville | 45k |
IV | Palo Alto | 56k |
IV | Daly City | 98k |
IV | Pajaro | 3k |
IV | Belvedere | 2k |
IV | Las Lomas | 3k |
IV | Woodside | 5k |
IV | Elkhorn | 1k |
IV | Grayson | 1k |
IV | Twin Lakes | 5k |
IV | San Ramon | 44k |
IV | Colma | 1k |
IV | Tiburon | 8k |
IV | Riverdale Park | 1k |
IV | West Menlo Park | 3k |
IV | Capitola | 9k |
IV | Foster City | 28k |
IV | Menlo Park | 29k |
IV | Union City | 66k |
IV | Discovery Bay | 11k |
IV | Opal Cliffs | 6k |
IV | Modesto | 216k |
IV | Tracy | 83k |
IV | Patterson | 15k |
IV | Stanford | 12k |
IV | Broadmoor | 4k |
IV | Atherton | 6k |
IV | Livermore | 80k |
III | Brentwood | 46k |
III | Country Club | 9k |
III | Salida | 17k |
III | Castro Valley | 62k |
III | Danville | 42k |
III | Burlingame | 26k |
III | San Francisco | 732k |
III | Corte Madera | 9k |
III | Prunedale | 22k |
III | Cherryland | 15k |
III | Ashland | 23k |
III | Emerald Lake Hills | 4k |
III | Shackelford | 5k |
III | Redwood City | 71k |
III | Castroville | 7k |
III | Stockton | 289k |
III | Larkspur | 11k |
III | Bystrom | 4k |
III | Lathrop | 13k |
III | Union City | 69k |
III | San Lorenzo | 23k |
III | Strawberry | 5k |
III | Mill Valley | 13k |
III | San Mateo | 89k |
III | Sausalito | 7k |
III | Belmont | 23k |
III | San Carlos | 26k |
III | Fairview | 9k |
III | Lincoln Village | 4k |
III | Hillsborough | 10k |
III | El Granada | 6k |
III | Manteca | 65k |
III | Ripon | 13k |
III | French Camp | 4k |
III | Boronda | 1k |
III | Oakley | 26k |
III | Millbrae | 19k |
III | Salinas | 148k |
III | August | 8k |
III | Hayward | 140k |
III | Kennedy | 3k |
III | Bethel Island | 2k |
III | Del Rio | 1k |
III | San Rafael | 55k |
III | Santa Venetia | 4k |
III | Pleasant Hill | 34k |
III | Moss Beach | 1k |
III | Alamo | 17k |
III | Newman | 8k |
III | Diablo | 1k |
III | Walnut Creek | 65k |
III | Ceres | 40k |
III | Kentfield | 6k |
III | Montara | 3k |
III | San Bruno | 39k |
III | Waldon | 5k |
III | Oakland | 399k |
III | Garden Acres | 10k |
III | South San Francisco | 58k |
III | Emeryville | 7k |
III | Gustine | 5k |
III | Ross | 2k |
III | Moraga | 16k |
III | Piedmont | 10k |
III | Martinez | 36k |
III | San Leandro | 79k |
III | Marina | 16k |
III | Lafayette | 24k |
III | Keyes | 5k |
III | Morada | 3k |
III | Seaside | 35k |
III | Empire | 4k |
III | Pacheco | 3k |
III | Escalon | 7k |
III | Mountain View | 2k |
III | San Pablo | 31k |
III | San Anselmo | 11k |
III | Los Banos | 33k |
III | Riverbank | 18k |
III | Pacifica | 36k |
III | Orinda | 18k |
III | Alameda | 70k |
III | Hughson | 6k |
III | Vine Hill | 3k |
III | Albany | 16k |
III | Fairfax | 7k |
III | Richmond | 103k |
III | Turlock | 67k |
III | Concord | 125k |
III | Crockett | 3k |
III | Antioch | 106k |
III | Hercules | 23k |
III | Pinole | 19k |
III | Pittsburg | 62k |
III | Suisun City | 27k |
III | Rio Vista | 7k |
III | Pacific Grove | 15k |
III | Brisbane | 3k |
III | Rollingwood | 3k |
III | Berkeley | 100k |
III | Bolinas | 1k |
III | Kensington | 4k |
III | East Richmond Heights | 3k |
III | Benicia | 26k |
III | El Cerrito | 23k |
III | Lodi | 62k |
III | Delhi | 11k |
III | Bay Point | 21k |
III | Linden | 1k |
III | Tara Hills | 5k |
III | El Sobrante | 13k |
III | Denair | 3k |
III | Oakdale | 18k |
III | Woodacre | 1k |
III | Clayton | 11k |
III | Fairfield | 105k |
III | Livingston | 12k |
III | Novato | 48k |
III | Atwater | 29k |
III | Rodeo | 9k |
III | Winton | 9k |
III | Waterford | 8k |
II | Lockeford | 3k |
II | East Oakdale | 2k |
II | Petaluma | 55k |
II | Galt | 23k |
II | Vallejo | 120k |
II | American Canyon | 15k |
II | South Dos Palos | 1k |
II | Dos Palos | 5k |
II | Green Valley | 1k |
II | Rancho Calaveras | 4k |
II | Valley Springs | 2k |
II | Inverness | 1k |
II | Copperopolis | 2k |
II | San Andreas | 2k |
II | Angels Camp | 2k |
I | Mountain Ranch | 1k |
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.