Earthquake swarm in western Iran

Here we find an earthquake swarm in western Iran. The convergence between the Afica and Indo-Australia plates with the Eurasia plates is evidenced by the subduction zone along Sumatra and Java, the uplift of the Himalayas, the fold and thrust belt in Iran (where this swarm is located), and subduction in the Mediterranean (and uplift of the Alps). Here is the USGS page for the largest magnitude earthquake of this swarm.

Here is the Mww moment tensor from the largest magnitude (M 6.2), supporting the interpretation of a northwest striking compressional earthquake. This is consistent with the northwest trending fold and thrust belt shown in the aerial imagery below.

This is a global scale map showing the plate boundaries in red and the epicenters in orange:

This is a larger scale map showing the regional fold and thrust belt in western Iran.

The USGS “pager” is an estimate of damage to people and their infrastructure. This estimate is generated by overlaying population information and building inventories with an estimate of ground shaking generated by a ground motion prediction model. This is only an estimate that is useful for emergency managers to use to determine the scope of any aid that might be offered or sent to the region.

Here is the USGS map of the plate boundaries and historic seismicity.

This image is a primer for us who want to learn more about focal mechanisms and moment tensors. Moment tensors and focal mechanisms are calculated in different ways, but their graphical depiction is largely the same. We may use this graphic to help us interpret the moment tensor of the M 6.2 earthquake shown above>

Category(s): College Redwoods, earthquake, education, geology, plate tectonics

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