ABAG Shaken
Awake! Report
Healdsburg-Rodgers Creek Earthquake
from
the 1996 report (NOT updated with 2003 data)
|
ABAG Shaken
Awake! Report |
|
|
|
from
the 1996 report (NOT updated with 2003 data)
|
Regional Map of Ground Shaking Intensity from the Healdsburg-Rodgers Creek Earthquake
This scenario earthquake is for a magnitude 7.1 earthquake on the Healdsburg-Rodgers Creek fault in Sonoma County.
As with other earthquakes that are centered on faults which are geographically removed from San Francisco or Alameda counties, the Healdsburg-Rodgers Creek earthquake causes almost as much damage in the County of San Francisco as in Sonoma County, where it is located. However, if the damage numbers for uninhabitability are looked at in terms of percentages of the total local housing stock, the damage is significant for Sonoma County; 8.5% of its local stock would be uninhabitable versus only 3.4% in San Francisco County.
The estimate for San Francisco includes over 11,000 uninhabitable units of which almost 78% were built before 1940. On the other hand, of the estimated 13,669 uninhabitable dwelling units in Sonoma County, only 9% are pre-1940 construction, since in Sonoma County only 11% of the total stock was constructed before 1940. The damage here is expected to occur mainly to mobile homes as 6,303 of them, which represent 53% of their total number, are expected to be uninhabitable.
Because the source of the event is located within Sonoma County, shelter needs are largest there, followed by the densely urbanized areas of San Francisco and Alameda counties.
In Sonoma County most of the shelter population is the result of red-tagged dwelling units (78%), while in San Francisco and Alameda counties most is the result of yellow-tagged units (70% and 63% respectively). This difference is the result of the impact of demographic factors in the output of shelter populations, particularly income and household type. While in San Francisco County most of the uninhabitable dwelling units are within multi-family buildings, in Sonoma County only half of them are in these buildings. The probability of individuals seeking shelter in the event of a major earthquake will be higher to residents of multi-family buildings within San Francisco and Alameda counties.
.
ABAG, the Association of Bay Area Governments, is the regional planning and services agency for the nine-county San Francisco Bay Area.This page was last updated 10/20/03 by jbp.
