Freezing temperatures and tiny natural seismic event
On Saturday, October 20th we reached a well head pressure sufficient to improve the permeability. Unfortunately, a cold snap late that night caused freezing conditions, from which we are still recovering. In addition, we discovered faulty logic boards controlling one of the stimulation pumps. Technicians are on site and we hope to get back to stimulation pressures early next week.
In the meantime, a natural microseismic event near the site was detected on October 24th at 11:05 pm, and displayed on the LBNL EGS site, the USGS site, and the PNSN site. The USGS/PNSN assigned a magnitude of -0.3 and LBNL a magnitude of 0.75. The USGS/PNSN magnitude is more accurate because it includes broadband seismometers and a site closer to the epicenter (WKBU on Figure below).
The epicenter was about 6 km from 55-29. Seven other very small (M<1.5) natural events like this have been detected since the improved seismic monitoring of Newberry has begun – see the red symbols labeled with the event date (like 2012/10/24) on the Google Earth image below.