Magnitude-6.9 earthquake hits off Alaska's Aleutian Islands

[Panich52]

Alaska Dispatch

Magnitude-6.9 earthquake hits off Alaska's Aleutian Islands
  
There were no immediate reports of damage and no tsunami was generated after a strong earthquake off the Aleutian Islands on Sunday night.

Alaska News | Alaska Dispatch News
Read more
http://www.adn.com/article/20150726/magnitude-69-earthquake-hits-alaskas-aleutian-islands

[Baclava]

1. Way out there, almost 1000 miles from Anchorage

[dixiegrrrrl]

3. Thanks for that.

When I lived in SF Bay area, I checked the earthquake map daily!
Surprising number of quakes of less than 3 mag. almost all the time, it seemed.

[Baclava]

4. Subduction zone - Pacific and N American plate grinding away at each other

There's some volcanoes that might be getting active too



https://www.avo.alaska.edu/activity/

[Brother Buzz]

5. Most of the Bay Area's earthquakes are attributed to the geothermal development ...

around Geyserville, just north Healdsburg, California.

Recent Earthquake Near Healdsburg, California:

11 earthquakes today
30 earthquakes in the past 7 days
122 earthquakes in the past month
1,571 earthquakes in the past year


According to the Lawrence Berkeley National Laboratory Earth Sciences division, seismicity was very low prior to the use of the Geyser steam field for geothermal energy, although this may have been the result of low seismic coverage of the area. Before 1969, there were no earthquakes above magnitude 2 recorded by the United States Geological Survey (USGS) in an approximately 70 square miles (180 km2) area around the Geysers. Studies have shown that injecting water into the Geysers field produces earthquakes from magnitude 0.5 to 3.0, although a 4.6 occurred in 1973 and magnitude four events increased thereafter. Even with increasing injection rates over time, the rate of magnitude 3 earthquakes has remained relatively unchanged since the 1980s, although the amount of earthquakes has increased significantly. A magnitude 4.5 earthquake struck near the Geysers on January 12, 2014. Despite the increases in the number of earthquakes and the fears of local residents, it is unlikely that a large earthquake will occur at the Geysers since there is no large earthquake fault or fracture nearby.

[Brother Buzz]

2. Followed by five aftershocks with a magnitude of 5.0 or greater!