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Publications

EPSL paper on slow earthquake in the Sea of Marmara

We recently published a paper in Earth and Planetary Science Letters entitled “Slow strain release along the eastern Marmara region offshore Istanbul in conjunction with enhanced local seismic moment release”.

The paper was quite widely commented in a GFZ press release, as well as in the Science Daily and Phys.org.

Full reference:

Martínez-Garzón, P., M. Bohnhoff, D. Mencin, G. Kwiatek, G. Dresen, K. Hodgkinson, M. Nurlu, F. T. Kadirioglu, and R. F. Kartal (2019). Slow strain release along the eastern Marmara region offshore Istanbul in conjunction with enhanced local seismic moment release, Earth and Planetary Science Letters 510, 209–218, DOI: 10.1016/j.epsl.2019.01.001.

Abstract:

We analyze a large transient strainmeter signal recorded at 62.5 m depth along the southern shore of the eastern Sea of Marmara region in northwestern Turkey. This region represents a passage of stress transfer from the Izmit rupture to the Marmara seismic gap. The strain signal was recorded at the Esenkoy site by one of the ICDP-GONAF (International Continental Drilling Programme – Geophysical Observatory at the North Anatolian Fault) strainmeters on the Armutlu peninsula with a maximum amplitude of 5 microstrain and lasting about 50 days. The onset of the strain signal coincided with the origin time of a MW 4.4 earthquake offshore Yalova, which occurred as part of a seismic sequence including eight MW ≥3.5 earthquakes. The MW 4.4 event occurred at a distance of about 30 km from Esenkoy on June 25th 2016 representing the largest earthquake in this region since 2008. Before the event, the maximum horizontal strain was subparallel to the regional maximum horizontal stress derived from stress inversion of local seismicity. During the strain transient, we observe a clockwise rotation in the local horizontal strain field of about 20°. The strain signal does not correlate with known environmental parameters such as annual changes of sea level, rainfall or temperature. The strain signal could indicate local slow slip on the Cinarcik fault and thus a transfer of stress to the eastern Marmara seismic gap.

Paper on SHEER project database within EPOS system

Some months ago Szymon Cielesta has published a paper that presents the development of SHEER database and its implementation in EPOS TCS Anthropogenic Hazard system.

Reference:

Cielesta, S., B. Orlecka-Sikora, M. Staszek, P. Urban, D. Olszewska, E. Ruigrok, S. Toon, M. Picozzi, G. Kwiatek, S. Cesca, J. A. López Comino, C. Isherwood, N. Montcoudiol, and J. Jarosławski (2018). SHEER “smart” database: technical note. Acta Geophysica. DOI: 10.1007/s11600-018-0205-3

Abstract:

The SHEER database brings together a large amount of data of various types: interdisciplinary site data from seven independent episodes, research data and those for the project results dissemination process. This concerns mainly shale gas exploitation test sites, processing procedures, results of data interpretation and recommendations. The smart SHEER database harmonizes data from different fields (geophysical, geochemical, geological, technological, etc.), creates and provides access to an advanced database of case studies of environmental impact indicators associated with shale gas exploitation and exploration, which previously did not exist. A unique component of the SHEER database comes from the monitoring activity performed during the project in one active shale gas exploration and exploitation site at Wysin, Poland, which started from the pre-operational phase. The SHEER database is capable of the adoption of new data such as results of other Work Packages and has developed an over-arching structure for higher-level integration.


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 ]

Paper in BSSA on focal mechanism of small earthquakes from the Salton Sea

Stephan Bentz published paper entitled “Sensitivity of Full Moment Tensors to Data Preprocessing and Inversion Parameters: A Case Study from the Salton Sea Geothermal Field”. The paper presents the results of investigation of mechanisms of approximately 80 small seismic events using two full seismic moment tensor inversion routines: the full waveform inversion and hybridMT code. The paper appeared in the Bulletin of Seismological Society of America.

Reference:

Bentz, Stephan, P. Martínez-Garzón, G. Kwiatek, M. Bohnhoff, and J. Renner (2018). Sensitivity of Full Moment Tensors to Data Preprocessing and Inversion Parameters: A Case Study from the Salton Sea Geothermal Field, Bull. Seismol. Soc. Am. DOI: 10.1785/0120170203.