EXAMPLES OF THE EFFECT OF SOURCE AND RECORDING SITE PARAMETERS ON THE SEISMIC RESPONSE OBSERVED FROM PLOWSHARE PROJECTS, GASBUGGY AND RULISON

Geophysics ◽  
1972 ◽  
Vol 37 (2) ◽  
pp. 288-300 ◽  
Author(s):  
Walter W. Hays
Keyword(s):  
Seismic Data ◽  
Spectral Response ◽  
Source Parameters ◽  
Sedimentary Basins ◽  
Test Site ◽  
Physical Parameters ◽  
Recording Site ◽  
Matrix Formulation ◽  
Surface Particle ◽  
Depth Of Burial

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.

PROCESSING AND IMAGING OF MARINE SEISMIC DATA FROM THE JEQUITINHONHA BASIN (BAHIA, BRAZIL)

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Lourenildo W.B. Leite ◽  
J. Mann ◽  
Wildney W.S. Vieira
Keyword(s):  
Seismic Data ◽  
Sedimentary Basins ◽  
Study Results ◽  
Marine Seismic ◽  
Present Case Study

ABSTRACT. The present case study results from a consistent processing and imaging of marine seismic data from a set collected over sedimentary basins of the East Brazilian Atlantic. Our general aim is... RESUMO. O presente artigo resulta de um processamento e imageamento consistentes de dados sísmicos marinhos de levantamento realizado em bacias sedimentares do Atlântico do Nordeste...

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

2002 ◽  
Vol 107 (B4) ◽  
pp. ESE 4-1-ESE 4-11 ◽  
Author(s):  
Antonella Amoruso ◽  
Luca Crescentini ◽  
Roberto Scarpa
Keyword(s):  
Seismic Data ◽  
Source Parameters

scholarly journals Constraints on the location, depth and yield of the 2017 September 3 North Korean nuclear test from InSAR measurements and modelling

2019 ◽  
Vol 220 (1) ◽  
pp. 345-351 ◽  
Author(s):  
K M Sreejith ◽  
Ritesh Agrawal ◽  
A S Rajawat
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Nuclear Explosion ◽  
Source Parameters ◽  
Test Site ◽  
Nuclear Test ◽  
Interferometric Synthetic Aperture Radar ◽  
Surface Displacements ◽  
Detailed Surface ◽  
Scale Surface

SUMMARY The Democratic People's Republic of Korea (North Korea) conducted its sixth and largest affirmed underground nuclear test on 2017 September 3. Analysis of Interferometric Synthetic Aperture Radar (InSAR) data revealed detailed surface displacements associated with the nuclear explosion. The nuclear explosion produced large-scale surface deformation causing decorrelation of the InSAR data directly above the test site, Mt. Mantap, while the flanks of the Mountain experienced displacements up to 0.5 m along the Line-of-Sight of the Satellite. We determined source parameters of the explosion using the Bayesian inversion of the InSAR data. The explosive yield was estimated as 245–271 kiloton (kt) of TNT, while the previous yield estimations range from 70–400 kt. We determined the nuclear source at a depth of 542 ± 30 m below Mt. Mantap (129.0769°E, 41.0324°N). We demonstrated that the Bayesian modelling of the InSAR data reduces the uncertainties in the source parameters of the nuclear test, particularly the yield and source depth that are otherwise poorly resolved in seismic methods.

THE EVOLUTION OF THE BERNIER RIDGE, SOUTHERN CARNARVON BASIN, WESTERN AUSTRALIA:IMPLICATIONS FOR PETROLEUM PROSPECTIVITY

2004 ◽  
Vol 44 (1) ◽  
pp. 241 ◽  
Author(s):  
A.M. Lockwood ◽  
C. D’Ercole
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Sedimentary Basins ◽  
Early Carboniferous ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Large Igneous Province ◽  
Satellite Gravity ◽  
Tectonic Events ◽  
Carnarvon Basin

The basement topography of the Gascoyne Platform and adjoining areas in the Southern Carnarvon Basin was investigated using satellite gravity and seismic data, assisted by a depth to crystalline basement map derived from modelling the isostatic residual gravity anomaly. The resulting enhanced view of the basement topography reveals that the Gascoyne Platform extends further westward than previously indicated, and is bounded by a northerly trending ridge of shallow basement, named the Bernier Ridge.The Bernier Ridge is a product of rift-flank uplift prior to the Valanginian breakup of Gondwana, and lies east of a series of small Mesozoic syn-rift sedimentary basins. Extensive magmatic underplating of the continental margin associated with this event, and a large igneous province is inferred west of the ridge from potential field and seismic data. Significant tectonic events that contributed to the present form of the Bernier Ridge include the creation of the basement material during the Proterozoic assembly of Rodinia, large-scale faulting during the ?Cambrian, uplift and associated glaciation during the early Carboniferous, and rifting of Gondwana during the Late Jurassic. The depositional history and maturity of the Gascoyne Platform and Bernier Ridge show that these terrains have been structurally elevated since the mid-Carboniferous.No wells have been drilled on the Bernier Ridge. The main source rocks within the sedimentary basins west of the Bernier Ridge are probably Jurassic, similar to those in the better-known Abrolhos–Houtman and Exmouth Sub-basins, where they are mostly early mature to mature and within the oil window respectively. Within the Bernier Ridge area, prospective plays for petroleum exploration in the Jurassic succession include truncation at the breakup unconformity sealed by post-breakup shale, and tilted fault blocks sealed by intraformational shale. Plays in the post-breakup succession include stratigraphic traps and minor rollover structures.

scholarly journals Methods and uncertainty-estimations of 3D structural modelling in crystalline rocks: A case study

2017 ◽  
Author(s):  
Raphael Schneeberger ◽  
Miguel De la Varga ◽  
Daniel Egli ◽  
Alfons Berger ◽  
Florian Kober ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Test Site ◽  
3D Models ◽  
Physical Parameters ◽  
Massif Central ◽  
Fault Pattern ◽  
Crystalline Bedrock ◽  
Surface Data ◽  
3D Geometry ◽  
Zone Pattern

Abstract. Exhumed basement rocks are often dissected by faults, the latter controlling physical parameters such as rock strength, porosity, or permeability. Knowledge on the three dimensional (3D) geometry of the fault pattern and its continuation with depth is therefore of paramount importance for projects of applied geology (e.g. tunnelling, nuclear waste disposals) in crystalline bedrock. The central Aar massif (Central Switzerland) serves as study area, where we investigate the 3D geometry of the Alpine fault pattern by means of both surface (fieldwork and remote sensing) and underground ground (mapping of the Grimsel Test Site) information. The fault zone pattern consists of planar steep major faults (kilometre-scale) being interconnected with secondary relay faults (hectometre-scale). Starting with surface data, we present a workflow for structural 3D modelling of the primary faults based on a comparison of three extrapolation approaches based on: a) field data, b) Delaunay triangulation and c) a best fitting moment of inertia analysis. The quality of these surface-data-based-3D models is then tested with respect to the fit of the predictions with the underground appearance of faults. All three extrapolation approaches result in

scholarly journals Indications for the Occurrence of Gas Hydrates in the Fram Strait from Heat Flow and Multichannel Seismic Reflection Data

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
W. H. Geissler ◽  
P. V. Pulm ◽  
W. Jokat ◽  
A. C. Gebhardt
Keyword(s):  
Heat Flow ◽  
Gas Hydrates ◽  
Seismic Data ◽  
Sedimentary Basins ◽  
Slope Instability ◽  
Western Slope ◽  
Fram Strait ◽  
Flow Data ◽  
Seismic Reflection Data ◽  
Yermak Plateau

The distribution of gas hydrates recently raised increased attention, especially along glaciated continental margins, due to its potential importance for slope stability and global climate. We present new heat flow data together with multichannel reflection seismic data from the central Fram Strait in-between Northeast Greenland and Svalbard. This area is only accessible by icebreaking vessels, and, therefore, knowledge about this area is still sparse. The new heat flow data concur with previous measurements in the region. High temperature gradients of >200 mK/m were recorded along the active spreading zone in the Fram Strait, and gradients of 75 mK/m along the western slope of Yermak Plateau. Along the Northeast Greenland slope, the measured gradients reach 54 mK/m at maximum. Seismic data image bottom-simulating reflections proofing that the known gas-hydrate province spreads much further north along the western slope of the Yermak Plateau than previously known. Existing slide scars indicate that there might be a causal relationship between the occurrence of gas hydrates and slope instability in that area. Along the Northeast Greenland continental margin and in the adjacent abyssal plain, strong indications for the occurrence of gas within the sedimentary basins and for its migration along fault zones and chimney-like structures are found.

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

1985 ◽  
Vol 22 (1) ◽  
pp. 126-132 ◽  
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.

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