What's going on in Northern California

OK, granted we're talking about California, which always shakes when it laughs like a bowl full of jelly, but this cluster in Northern Cali looks interesting to me:



MAP 2.3 2010/07/10 21:02:39 40.728 -123.293 23.9 21 km ( 13 mi) NW of Hayfork, CA
MAP 1.9 2010/07/10 16:11:57 40.306 -124.280 4.5 2 km ( 1 mi) S of Petrolia, CA
MAP 3.8 2010/07/10 16:04:30 40.429 -123.564 32.2 39 km ( 24 mi) WSW of Hayfork, CA
MAP 3.0 2010/07/10 03:11:21 40.288 -124.361 8.3 8 km ( 5 mi) WSW of Petrolia, CA
MAP 1.8 2010/07/10 01:25:07 40.297 -124.291 4.2 3 km ( 2 mi) S of Petrolia, CA

Seems like quite a few medium sized shakes for one day, I wouldn't think anything of it had there been a larger quake in the area lately, but I don't think they are aftershocks. (Could be from that 7.x last summer this January but it seems unlikely.) Foreshock sequence? This is not one of those geothermal plant areas in CA that are constantly shaking.

Just being speculative. We'll see what happens this week.

Map:
earthquake.usgs.gov...

This is right around the Mendocino Triple Junction so it's a prime region for larger quakes.

woodshole.er.usgs.gov...

[edit on 10-7-2010 by quakewatcher]

Wow, normally I hear of alot of activity in southern CA, but NORTHERN got my attention. I am between Redding and Sacramento.

Please keep us updated.. I wonder what would happen to the fault line if it opened up at both ends, but not in the center?
Maybe the center isnt showing as much because of the depth.

Nothing really going on up there by the triple junction any more, but today there was a slightly bigger than usual quake at the Geysers (which is just constantly shaking and has been since the power plant opened there) followed by an aftershock of similar magnitude.

MAP 3.8 2010/07/15 23:54:20 38.814 -122.814 2.1 2 km ( 1 mi) NNW of The Geysers, CA
MAP 1.1 2010/07/15 23:01:15 38.829 -122.761 1.3 3 km ( 2 mi) W of Cobb, CA
MAP 1.5 2010/07/15 20:55:48 38.838 -122.772 2.0 4 km ( 3 mi) W of Cobb, CA
MAP 1.0 2010/07/15 20:45:56 38.826 -122.813 3.7 3 km ( 2 mi) N of The Geysers, CA
MAP 1.0 2010/07/15 19:43:28 38.932 -122.837 21.4 5 km ( 3 mi) S of Kelseyville, CA
MAP 2.0 2010/07/15 19:29:07 38.824 -122.805 2.7 3 km ( 2 mi) N of The Geysers, CA
MAP 1.2 2010/07/15 19:14:14 38.761 -122.732 2.4 4 km ( 2 mi) WSW of Anderson Springs, CA
MAP 1.1 2010/07/15 15:57:21 38.812 -122.813 2.9 2 km ( 1 mi) NNW of The Geysers, CA
MAP 1.3 2010/07/15 15:46:49 38.816 -122.817 2.6 2 km ( 1 mi) NNW of The Geysers, CA
MAP 1.4 2010/07/15 15:42:04 38.825 -122.806 3.0 3 km ( 2 mi) N of The Geysers, CA
MAP 1.1 2010/07/15 15:35:12 38.819 -122.812 2.0 2 km ( 1 mi) N of The Geysers, CA
MAP 2.5 2010/07/15 15:33:25 38.814 -122.774 0.0 3 km ( 2 mi) ENE of The Geysers, CA
MAP 4.0 2010/07/15 15:31:43 38.819 -122.807 2.7 2 km ( 1 mi) N of The Geysers, CA

I continue to think the Northern portion of CA is up to something interesting this week.