Hi Chris,

My daughter and I were just texting, spectulating on the absence of aftershocks 2 - both less than 4.0 and also, whether the 6.3 quake on April 9th a couple of hubdred miles to the NW, which had a healthy aftershock sequence, may have triggered the 7.8. I think that USGS has re-analyzed the depth and decided on 50 km., which still seems deep in a region where oil seeps from the ground, albeit, perhaps not exactly in this location! I'm wondering if, due to the location, the few aftershocks, etc., and what little I know, if this may be a foreshadowing event? Perhaps this is not over yet?

I did read that the SE coast of Iran, and I think that this qualifies, that "the Makran trench is the present-day surface expression of active subduction of the Arabia plate beneath the continental Eurasia plate, which converge at a rate of approximately 20 mm/yr. Although the Makran subduction zone has a relatively slow convergence rate, it has produced large devastating earthquakes and tsunamis. For example, the November 27, 1945 M8.0 mega-thrust earthquake produced a tsunami within the Gulf of Oman and Arabia Sea, killing over 4,000 people. Northwest of this active subduction zone, collision of the Arabia and Eurasia plates forms the approximately 1,500-km-long fold and thrust belt of the Zagros Mountains, which crosses the whole of western Iran and extends into northeastern Iraq. Collision of the Arabia and Eurasia plates also causes crustal shortening in the Alborz Mountains and Kopet Dag in northern Iran. Eastern Iran experiences destructive earthquakes that originate on both strike-slip and reverse faults. For example, the 16 September 1978 M7.8 earthquake, along the southwest edge of the Dasht-e-Lut Basin killed at least 15,000 people."

Thus, subduction forces could produce something much greater, in theory, anyway. Of course, for all I know, they could be setting off underground nuclear bombs!

Love to have some input, as I am so bored and sick of being sick!
Beth

• About tectonics in the Middle East