Gravitational mapping of underground rock in Nevada to help assess earthquake risk

What is it about?

Earthquakes cause more death and destruction each year than any other type of natural disaster. But much of that can be prevented with proper mitigation in the construction of new buildings and bridges. To do that, engineers need to know the magnitude and duration of shaking to be expected in the area during an earthquake. And to predict that, one needs to know the density and depth of the sedimentary rock below the area of interest. This is because deep, low-density basins shake much more than shallow, dense basin areas. As a result, communities planning significant new construction are in the most need of accurate basin depth and density research. To assist with that, we studied an area north of Reno, Nevada called Lemmon Valley that is undergoing rapid urban development by collecting high-precision gravity measurements. We used those measurements to map out the most likely depth, shape, and density of rock under the ground. Importantly, we found a low-density basin of sedimentary rock 5 km long, 2 km wide, and 800 meters deep just west of the Reno-Stead airport which could greatly amplify earthquake waves. We created a detailed 3D map of the underground rock and that map has already been incorporated into the computer models used to predict earthquake shaking hazards in the area. This improved model will help city planners and engineers design buildings and infrastructure that can better withstand future earthquakes.

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Photo by GeoJango Maps on Unsplash

Photo by GeoJango Maps on Unsplash

Why is it important?

see above

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