Update 3.8.1 to foci software package

New version (3.8.1) of foci software package has been released recent week. This version brings some new features that will be developed in next months:

– Introduction of inelastic attenuation correction in calculation of full seismic moment tensor.
– Multiple corrections to preferences window.
– Introduction of foci package into github version control system
– Code cleanup.

The polish version of foci website has been also rearranged and refurbished. This is the first step to translate this page into english.

Building up page on The Geysers studies

The Geysers represents a unique site for analysis of induced seismicity. This vapor-dominated geothermal field is located about 120 km north of San Francisco where the geothermal power production is performed for more than 50 years. Currently, The Geysers is the world’s largest geothermal field operated by Calpine and spanning an area of around 78km2 with the nominal capacity of 1517 MW. It is also an area of intensive induced seismic activity, with the largest event reaching magnitude 5.0. The seismicity is recorded with an extensive seismic monitoring networks operated by Lawrence Berkeley National Laboratory, and broadband regional network.

The availaibility of high quality data triggered our interest in understanding seismo-mechanical processes in this reservoir. This resulted in a number of publications, that I decided to gather in one place – The Geysers resesarch page.

Paper on Acoustic Emission activity during hydraulic fracturing experiment in Äspö, Sweden

We published a new paper in the Journal of Geophysical Research: Solid Earth related to the hydraulic fracture experiments performed in 2015 in  Äspö Hard Rock Laboratory, Sweden. Here are the highlights:

  • We analyze source characteristics of picoseismicity (moment magnitudes smaller than -3.5!) related to hydraulic stimulations in Äspö Hard Rock Laboratory, Sweden.
  • We show that spatio-temporal seismicity migration is controlled by changes in hydraulic (pressure times volume) energy.
  • We present that total radiated seismic energy is very low with respect to injected volume, and increases with hydraulic energy rate.

The reference:

Kwiatek, G., Martínez-Garzón, P., Plenkers, K., Leonhardt, M., Zang, A., Specht, S., et al. (2018). Insights Into Complex Subdecimeter Fracturing Processes Occurring During a Water Injection Experiment at Depth in Äspö Hard Rock Laboratory, Sweden. Journal of Geophysical Research: Solid Earth, DOI: 10.1029/2017JB014715. [ Article Page ]

Paper on earthquake clustering in hydrothermal reservoirs

We published another paper on induced seismicity, this time related to the clustering properties of induced seismicity observed in a couple of hydrothermal reservoirs. Here is the reference:

Martínez-Garzón, P., I. Zaliapin, Y. Ben-Zion, G. Kwiatek, and M. Bohnhoff (2018). Comparative Study of Earthquake Clustering in Relation to Hydraulic Activities at Geothermal Fields in California. Journal of Geophysical Research: Solid Earth, 123. DOI: 10.1029/2017JB014972 [ Article Page ]