Source parameters of the 1908 Messina Straits, Italy, earthquake from geodetic and seismic data

The amplitude and frequency composition of the seismic motions observed over a wide geographic area from Gasbuggy and Rulison, two Plowshare detonations, illustrates the effect which source and recording site parameters have on the resultant ground motion. Gasbuggy (29 kt) and Rulison (40 kt) were detonated, respectively, in the San Juan and Piceance Creek sedimentary basins of New Mexico and Colorado. Because both detonations were emplaced in sedimentary formations to stimulate the flow of natural gas, these detonations were placed at a greater depth of burial than typically required for containment. The effect of source parameters (device depth of burial and energy release) was simulated by seismic scaling theory. This theory (based on an extension of Sharpe’s problem) predicted a smaller elastic radius and, consequently, higher dominant frequency of generation for the elastic waves than would be expected on the basis of Nevada Test Site experience with typically contained events of 29 and 40 kt. Observed effects of the source variables were displayed in the Gasbuggy and Rulison seismic data: (1) a shift of the frequency of maximum spectral response to the high frequency end of the spectrum and (2) enhancement of the peak vector surface particle accelerations and velocities and a decrease in the peak vector surface particle displacements. Some of the Rulison recording sites were located on thin (50 ft thick or less) layers of alluvium which, on the basis of refraction surveys, exhibited a fairly significant contrast in acoustic impedance relative to that of the underlying sedimentary rocks. The effect of the lowvelocity alluvium layers at recording sites of interest was simulated by amplitude amplification modeling (based on the Haskell‐Thompson matrix formulation) using interpreted data from refraction surveys to define the layer physical parameters. These calculations indicated that significant local frequency‐dependent amplification would occur at some locations in the Piceance Creek Basin, a prediction which was verified by the seismic data.

Download Full-text

Source parameters of the Ensenada Bay earthquake swarm, Baja California, Mexico

Canadian Journal of Earth Sciences ◽

10.1139/e85-010 ◽

1985 ◽

Vol 22 (1) ◽

pp. 126-132 ◽

Cited By ~ 3

Author(s):

Cecilio J. Rebollar

Keyword(s):

Seismic Data ◽

Strain Energy ◽

High Strain ◽

Source Parameters ◽

Earthquake Swarm ◽

Ground Displacement ◽

Source Dimensions ◽

Fault Type ◽

Stress Drops ◽

High Strain Energy

Seismic data collected from the Ensenada Bay earthquake swarm of late 1981 were used to calculate the spectra of ground displacement. Data from the stations of Ensenada (ENX) and Cerro Bola (CBX), at epicentral distances of 14 and 57 km, respectively, were used to evaluate source parameters. The focal depths determined for these events were less than 10 km. The focal mechanism was a strike-slip fault type, with the plane of motion striking N52°W, parallel to the Agua Blanca Fault. Seismic moments ranging from 3.44 × 1019 to 5.99 × 1020 dyn∙cm (3.44 × 1014 to 5.99 × 1015 N∙cm) were estimated for events with local magnitudes in the range 1.7–2.3. The source dimensions were found to be 186 ± 36 m and the stress drops between 3 and 66 bar (0.3 and 6.6 MPa), comparable to results obtained in previous studies of shallow events (depths <10 km). The Ensenada swarm could be attributed to a localized zone of high-strain energy at the intersection of two faults. Ratios of P to S corner frequencies were evident for only five events; they were 1.39 ± 0.38. Magnitude and seismic moment from other studies were compared with the Ensenada data in the range of magnitudes 0–3. All the data can be accommodated by log M0 = 1.5 ML + (16.9 ± 1.1). The Ensenada earthquake swarm and the Victoria earthquake swarm, which occurred in the Mexicali valley in 1978, have similar source radii and corner frequencies for the same range of seismic moments.

Download Full-text

Fault-plane solutions and source parameters of the 1992 Roermond, the Netherlands, mainshock and its stronger aftershocks from regional seismic data

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(96)87390-6 ◽

1996 ◽

Vol 33 (1) ◽

pp. A7

Keyword(s):

The Netherlands ◽

Seismic Data ◽

Fault Plane ◽

Source Parameters ◽

Fault Plane Solutions

Download Full-text

Estimating the 2008 Quetame (Colombia) earthquake source parameters from seismic data and InSAR measurements

Journal of South American Earth Sciences ◽

10.1016/j.jsames.2016.09.011 ◽

2016 ◽

Vol 72 ◽

pp. 250-265 ◽

Cited By ~ 5

Author(s):

Gabriel Dicelis ◽

Marcelo Assumpção ◽

James Kellogg ◽

Patricia Pedraza ◽

Fábio Dias

Keyword(s):

Seismic Data ◽

Source Parameters ◽

Earthquake Source ◽

Earthquake Source Parameters

Download Full-text

An earthquake catalogue for seismic events in the Norman Wells region of the central Mackenzie Valley, Northwest Territories, using waveform data from local seismic stations

10.4095/328953 ◽

2021 ◽

Author(s):

A M Farahbod ◽

H Kao ◽

D Snyder

Keyword(s):

Northwest Territories ◽

Seismic Data ◽

Source Parameters ◽

Energy Industry ◽

Dense Array ◽

Waveform Data ◽

Seismicity Distribution ◽

Multi Stage ◽

Test Operations ◽

Seismograph Network

The development of unconventional hydrocarbon resources in the Norman Wells region of the Central Mackenzie Valley, Northwest Territories, has been explored by the energy industry. In early 2014, Conoco-Philips Canada conducted two multi-stage test operations of hydraulic fracturing (HF) in the region. In this study, we combine seismic data from the Canadian National Seismograph Network, four new stations established by the Northwest Territories Geoscience Office in collaboration with Natural Resources Canada in the Norman Wells region, and a local dense array installed by Conoco-Philips Canada to study the seismicity distribution during the pre-HF, HF and post-HF periods. We have identified and located 130 earthquakes within 100 km of the geographic centre of the local seismic network near Norman Wells for the pre-HF period (11 September 2013 - 7 February 2014). In comparison, 231 events are located during the HF period (8 February 2014 - 10 March 2014), and for the two post-HF periods, 11 March 2014 - 31 July 2014 and 27 February 2015 - 31 December 2015, we have catalogued 255 and 138 events, respectively. Source parameters and detailed phase pickings of each earthquake are given in the Appendices.

Download Full-text