Earthquakes and Tsunamis are Most Destructive Forces of Nature

Earthquakes and Tsunamis are the most destructive forces of nature which might be more of a threat than current estimates. This study was published in Nature Geoscience.The researchers developed a new technique to assess earthquake and tsunami hazards represented by the most distant part of offshore subduction zones. They also found that the hazard might have been systematically underestimated in some areas, meaning that tsunami risk assessments should be redone given the new results. These findings have significant implications for the mitigation of risk in affected areas worldwide, including Southeast Asia and the Pacific Rim, in the event of future Earthquakes and Tsunamis.

Megathrust earthquakes are among the most powerful earthquakes experienced worldwide and occur in subduction zones, where two tectonic plates converge, and one slides under the other. The plates move toward each other continuously, but if the interface, or fault, between them is stuck, then a slip deficit builds up over time. Earthquakes affect the shallowest part of the fault near the seafloor, they have the potential to shift the seafloor upward and create devastating tsunamis as well.

The probable rupture behaviour of mega thrusts in the shallow offshore part of the fault where most destructive tsunamis are generated is, therefore, a critical task for geoscientists forecasting seismic and tsunami inundation hazards. The likelihood of seismic behavior is assumed to be low in the shallow part of the fault, based on laboratory studies of recovered fault zone material.

Eric Lindsey, an assistant professor in the UNM Department of Earth and Planetary Sciences Said that they applied the technique to the Cascadia and Japan subduction zones and found that wherever deeper locked patches are present, the shallow fault must also have a high slip deficit regardless of its frictional properties.