This natural color Landsat 8 image of the Sacramento Valley area shows the impacts of the relentless rains that impacted the area during the end of December and into the New Year. Turbid river water, saturated fields, and rising reservoirs can be seen near Stockton and Sacramento.
Can large amounts of rain in California cause an increase in earthquakes?
There is no pattern in California of large, damaging earthquakes occurring more frequently during periods of heavy precipitation or periods of drought. Therefore, it’s unlikely that seismic hazard is affected by precipitation. This makes sense as rainwater cannot easily percolate several kilometers below the earth's surface to the depths where most earthquakes occur.
However, periods of heavy precipitation or of drought might indirectly affect earthquake-prone faults. For example, patterns of precipitation can affect the weight of near-surface materials and of reservoirs. Also the refilling of subsurface aquifers may cause the Earth’s crust to expand (by a few millimeters) in some locations and contract in others, with the opposite occurring during dry periods. These can cause small changes in the stresses on faults that--in principle--could slightly influence rates of seismicity.
A few studies have found that rates of microearthquakes in California may undergo small variations that are likely related to precipitation patterns. For example, scientists at Stony Brook University studied continuous records of motion from Global Navigation Satellite Systems (GNSS) to detect annual cycles of expansion and contraction of the Earth’s surface, and related them to patterns and intensity of precipitation. Using computer models, they demonstrated that annual variations in stress on California’s faults are larger during years of unusually heavy precipitation or drought. This 2021 study concluded that slightly more earthquakes might be expected in portions of eastern California during winters with heavy precipitation than in winters of drought, and, in contrast, that slightly fewer earthquakes might be expected on the San Andreas Fault during heavy precipitation winters in comparison to normal or drought winters.
Additional studies suggest that a large water load that’s uniformly distributed during the rainy season can suppress seismicity, while surface water that is unevenly distributed (for example water that's concentrated in a valley or on a mountain) has a small potential to increase seismicity. This is an area of ongoing research.
Related Content
Can you predict earthquakes?
No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur ( shown on our hazard mapping ) in a specific area within a certain number of years. An earthquake prediction must define 3 elements...
Do solar flares or magnetic storms (space weather) cause earthquakes?
Solar flares and magnetic storms belong to a set of phenomena known collectively as "space weather". Technological systems and the activities of modern civilization can be affected by changing space-weather conditions. However, it has never been demonstrated that there is a causal relationship between space weather and earthquakes. Indeed, over the course of the Sun's 11-year variable cycle, the...
Are earthquakes associated with variations in the geomagnetic field?
Electromagnetic variations have been observed after earthquakes, but despite decades of work, there is no convincing evidence of electromagnetic precursors to earthquakes. It is worth acknowledging that geophysicists would actually love to demonstrate the reality of such precursors, especially if they could be used for reliably predicting earthquakes! Learn more: USGS Geomagnetism Program
Can "MegaQuakes" really happen? Like a magnitude 10 or larger?
No, earthquakes of magnitude 10 or larger cannot happen. The magnitude of an earthquake is related to the length of the fault on which it occurs. That is, the longer the fault, the larger the earthquake. A fault is a break in the rocks that make up the Earth's crust, along which rocks on either side have moved past each other. No fault long enough to generate a magnitude 10 earthquake is known to...
Will California eventually fall into the ocean?
No, California is not going to fall into the ocean. California is firmly planted on the top of the earth’s crust in a location where it spans two tectonic plates. The San Andreas Fault System, which crosses California from the Salton Sea in the south to Cape Mendocino in the north, is the boundary between the Pacific Plate (that includes the Pacific Ocean) and North American Plate (that includes...
Is there earthquake weather?
In the 4th Century B.C., Aristotle proposed that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory lead to a belief in earthquake weather, that because a large amount of air was trapped underground, the weather would be hot and calm before an...
Landsat 8 Image of Sacramento Valley on Jan 22, 2023
This natural color Landsat 8 image of the Sacramento Valley area shows the impacts of the relentless rains that impacted the area during the end of December and into the New Year. Turbid river water, saturated fields, and rising reservoirs can be seen near Stockton and Sacramento.
Earthquake Damage on California Hwy. 178
A fault offset on California State Route 178 following the Magnitude 6.4 earthquake that struck Searles Valley on July 4, 2019.
A fault offset on California State Route 178 following the Magnitude 6.4 earthquake that struck Searles Valley on July 4, 2019.
Santa Maria River Flooding
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
Rainstorms can be localized or widespread.
A localized heavy summer rainstorm in Colorado.
A localized heavy summer rainstorm in Colorado.
Lateral Spread Caused by Liquefaction
A damaged road caused by liquefaction lateral spread. The photo was taken in California after the 1989 Loma Prieta earthquake.
A damaged road caused by liquefaction lateral spread. The photo was taken in California after the 1989 Loma Prieta earthquake.
Related Content
- FAQ
Can you predict earthquakes?
No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur ( shown on our hazard mapping ) in a specific area within a certain number of years. An earthquake prediction must define 3 elements...
Do solar flares or magnetic storms (space weather) cause earthquakes?
Solar flares and magnetic storms belong to a set of phenomena known collectively as "space weather". Technological systems and the activities of modern civilization can be affected by changing space-weather conditions. However, it has never been demonstrated that there is a causal relationship between space weather and earthquakes. Indeed, over the course of the Sun's 11-year variable cycle, the...
Are earthquakes associated with variations in the geomagnetic field?
Electromagnetic variations have been observed after earthquakes, but despite decades of work, there is no convincing evidence of electromagnetic precursors to earthquakes. It is worth acknowledging that geophysicists would actually love to demonstrate the reality of such precursors, especially if they could be used for reliably predicting earthquakes! Learn more: USGS Geomagnetism Program
Can "MegaQuakes" really happen? Like a magnitude 10 or larger?
No, earthquakes of magnitude 10 or larger cannot happen. The magnitude of an earthquake is related to the length of the fault on which it occurs. That is, the longer the fault, the larger the earthquake. A fault is a break in the rocks that make up the Earth's crust, along which rocks on either side have moved past each other. No fault long enough to generate a magnitude 10 earthquake is known to...
Will California eventually fall into the ocean?
No, California is not going to fall into the ocean. California is firmly planted on the top of the earth’s crust in a location where it spans two tectonic plates. The San Andreas Fault System, which crosses California from the Salton Sea in the south to Cape Mendocino in the north, is the boundary between the Pacific Plate (that includes the Pacific Ocean) and North American Plate (that includes...
Is there earthquake weather?
In the 4th Century B.C., Aristotle proposed that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory lead to a belief in earthquake weather, that because a large amount of air was trapped underground, the weather would be hot and calm before an...
- Multimedia
Landsat 8 Image of Sacramento Valley on Jan 22, 2023
This natural color Landsat 8 image of the Sacramento Valley area shows the impacts of the relentless rains that impacted the area during the end of December and into the New Year. Turbid river water, saturated fields, and rising reservoirs can be seen near Stockton and Sacramento.
This natural color Landsat 8 image of the Sacramento Valley area shows the impacts of the relentless rains that impacted the area during the end of December and into the New Year. Turbid river water, saturated fields, and rising reservoirs can be seen near Stockton and Sacramento.
Earthquake Damage on California Hwy. 178A fault offset on California State Route 178 following the Magnitude 6.4 earthquake that struck Searles Valley on July 4, 2019.
A fault offset on California State Route 178 following the Magnitude 6.4 earthquake that struck Searles Valley on July 4, 2019.
Santa Maria River FloodingA USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
Rainstorms can be localized or widespread.A localized heavy summer rainstorm in Colorado.
A localized heavy summer rainstorm in Colorado.
Lateral Spread Caused by LiquefactionA damaged road caused by liquefaction lateral spread. The photo was taken in California after the 1989 Loma Prieta earthquake.
A damaged road caused by liquefaction lateral spread. The photo was taken in California after the 1989 Loma Prieta earthquake.
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