Very shallow M6.6 earthquake hits Ogasawara region, Japan
A very shallow earthquake registered by the JMA as M6.6 hit Japanese Ogasawara Archipelago at 18:22 UTC (03:22 JST) on August 16, 2018. The USGS is reporting M6.4 at a depth of 11.5 km (7.1 miles) at 18:21 and M6.0 at 18:22 UTC. EMSC is reporting M6.4 and M5.9 at a depth of 10 km (6.2 miles). According to the USGS, the epicenter was located 251 km (156 miles) SE of Iwo Jima, 420.9 km (261.5 miles) SSW of Ogasawara, Japan and 945.4 km (587.5 miles) NNW of Saipan, Northen Mariana Islands. There are no people living within 100 km (62 miles). Although there may be slight sea-level changes in coastal regions, this earthquake has caused no damage to Japan, JMA said. The closest volcanoes are Minami-Hiyoshi and Nikko, both submarine. They have located roughly 100 km (62 miles) W of the epicenter. Periodic water discoloration and water-spouting have been reported over Minami-Hiyoshi since 1975 when detonations and an explosion were als…


Image result for interplanetary shock wave
An interplanetary shock wave hit Earth's magnetic field on April 19th around 23:50 UT. When the shock arrived, the density of the solar wind flowing around our planet abruptly quadrupled. Moreover, magnetic fields in the solar wind near Earth have since intensified 10-fold. These developments set the stage for possible geomagnetic storms in the hours ahead.

Auroras are now being reported in northern Michigan. S. Evans sends this picture from Big Bay, MI:

"The auroras are brightening after midnight on April 20th with some rays and beams, and good color," says Evans.
What is an interplanetary shock wave? It is a supersonic disturbance in the gaseous material of the solar wind. These waves are frequently delivered by coronal mass ejections (CMEs). Indeed, this one might have been a minor CME that left the sun unrecognized earlier this week. Or it might be an unusually sharp co-rotating interaction region (CIR). CIRs are transition zones between slow- and fast-moving streams of solar wind. They contain plasma density gradients that often do a good job of sparking auroras.


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