There is not only an elevated risk of large earthquakes in the San Francisco area. Nope! The ground around San Francisco Bay is sinking and is set to meet the rising sea in about 80 years. Now, a new scientific study adds up to this already growing fear of drowning, reporting that this land subsidence will increase the potential reach and damage of flooding in the Bay Area, submerging a larger portion of the region by the year 2100 than previously estimated. Yes, Bay Area residents you should start to worry about your home and protect your next generations from the Big Drowning.
The authors of the report have combined land elevation data with rising sea level projections. And they are now challenging the current flood threat projections as too conservative and hope that their new findings will help cities and agencies produce more accurate hazard maps, updating the extent of affected areas.
Under the new projections, San Francisco International Airport could see half of its runways submerged by the year 2100. Original estimates that did not include land subsidence were much lower. Other areas around the Bay that have been built on engineered landfill, like parts of Foster City and Treasure Island, are particularly vulnerable to the dual impact of subsidence and sea level rise.
The combination of rising sea levels and sinking ground increases estimates of the total amount of endangered areas to a range of 48 to 166 square miles. The rate of sink plays a role in the severity of the estimate: While most areas around the Bay are sinking at less than two millimeters per year, some have been found to be sinking at a rate as high as 10 millimeters per year.
It’s a very well-known problem, but we really don’t know how fast it’s going to be in the second half of the 21st century. This is a projection. Hopefully a wrong one for California!