On: “Search for Geothermal Siesmic Noise in the East Mesa Area, Imperial Valley, California,” by H. M. Iyer (GEOPHYSICS, December 1975, p. 1066–1072)

Geophysics ◽  
1976 ◽  
Vol 41 (3) ◽  
pp. 542-542
Author(s):  
Lewis J. Katz
Keyword(s):  
Geophysical Methods ◽  
Geological Structure ◽  
Well Log ◽  
Noise Sources ◽  
Imperial Valley ◽  
Geothermal Exploration ◽  
Long Valley ◽  
Exploration Tool ◽  
Cultural Noise ◽  
Inversion Techniques

Dr. Iyer rightfully points out that cultural noise sources (e.g., traffic, canals) tend to mask smaller amplitude geothermally generated microtremors. These problems have been recognized by other investigators as well. However, we take exception to his conclusions questioning the validity of groundnoise surveys as a geothermal exploration tool based solely on this study or his other survey in Long Valley, California where he had 1000 head of cattle nibbling on his geophones. Areas adjacent to cultural noise generators are not meant to be surveyed by this technique, as he points out. But what of the hundreds of other areas that are culturally silent? Results from these areas have yet to be weighed. Preliminary results from suitably applicable areas appear to have favorable indications. One prospect drilled on a groundnoise anomaly has been confirmed as a major geothermal find. Crustal inversion techniques applied to groundnoise spectra have been used to interpret geological structure. Gravity and resistivity profiles, and well log information over the same areas, have verified the groundnoise interpretations. As with many other geophysical methods, groundnoise should be used as a reconnaissance tool or in conjunction with other surveys.

Reply by author to discussion by L. J. Katz and W. D. Wagner

Geophysics ◽  
1976 ◽  
Vol 41 (3) ◽  
pp. 542-543
Author(s):  
H. M. Iyer
Keyword(s):  
High Velocity ◽  
Seismic Noise ◽  
Geothermal System ◽  
Imperial Valley ◽  
Geothermal Exploration ◽  
Long Valley ◽  
Exploration Tool ◽  
Ground Noise ◽  
Favorable Conditions

Nowhere in my paper have I questioned the validity of ground noise surveys as a geothermal exploration tool. My conclusions are specifically for the Mesa geothermal anomaly in Imperial Valley, California. I do believe that geothermal seismic noise exists and can be detected under favorable conditions, as was shown at Yellowstone (Iyer and Hitchcock, 1974). At Long Valley, in spite of “1000 head of cattle nibbling” at my geophones (did Drs. Katz and Wagner get the word from the cow’s mouth, perhaps) we found indications of “high‐velocity” seismic noise associated with the geothermal system in the area (Iyer and Hitchcock, 1976).

scholarly journals Integrated magnetotelluric and seismic investigation of Cenozoic graben structure near Obrzycko, Poland

2021 ◽  
Author(s):  
Adam Cygal ◽  
Michał Stefaniuk ◽  
Anna Kret
Keyword(s):  
Seismic Data ◽  
Geophysical Methods ◽  
Geological Structure ◽  
Data Sets ◽  
Low Velocity ◽  
Shallow Subsurface ◽  
Geophysical Model ◽  
Novel Approach ◽  
Loose Deposits ◽  
Static Corrections

AbstractThis article presents the results of an integrated interpretation of measurements made using Audio-Magnetotellurics and Seismic Reflection geophysical methods. The obtained results were used to build an integrated geophysical model of shallow subsurface cover consisting of Cenozoic deposits, which then formed the basis for a detailed lithological and tectonic interpretation of deeper Mesozoic sediments. Such shallow covers, consisting mainly of glacial Pleistocene deposits, are typical for central and northern Poland. This investigation concentrated on delineating the accurate geometry of Obrzycko Cenozoic graben structure filled with loose deposits, as it was of great importance to the acquisition, processing and interpretation of seismic data that was to reveal the tectonic structure of the Cretaceous and Jurassic sediments which underly the study area. Previously, some problems with estimation of seismic static corrections over similar grabens filled with more recent, low-velocity deposits were encountered. Therefore, a novel approach to estimating the exact thickness of such shallow cover consisting of low-velocity deposits was applied in the presented investigation. The study shows that some alternative geophysical data sets (such as magnetotellurics) can be used to significantly improve the imaging of geological structure in areas where seismic data are very distorted or too noisy to be used alone

scholarly journals Seismic Methods in Geothermal Water Resource Exploration: Case Study from Łódź Trough, Central Part of Poland

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tomasz Maćkowski ◽  
Anna Sowiżdżał ◽  
Anna Wachowicz-Pyzik
Keyword(s):  
Estimation Error ◽  
Geophysical Methods ◽  
Petroleum Industry ◽  
Geological Structure ◽  
Seismic Survey ◽  
Energy Potential ◽  
Geothermal Resources ◽  
Geothermal Waters ◽  
Seismic Methods ◽  
Geophysical Surveys

The geothermal waters constitute a specific type of water resources, very important from the point of view of their thermal energy potential. This potential, when utilized, supplies an ecological and renewable energy, which, after effective development, brings many environmental, social, and industrial benefits. The key element of any geothermal investment is the proper location of geothermal installation, which would guarantee the relevant hydrogeothermal parameters of the water intake. Hence, many studies and analyses are carried out in order to characterize the reservoir parameters, including the integrated geophysical methods. For decades, the geophysical surveys have been the trusty recognition methods of geological structure and petrophysical parameters of rock formations. Thus, they are widely applied by petroleum industry in exploration of conventional and unconventional (shale gas/oil, tight gas) hydrocarbon deposits. Advances in geophysical methods extended their applicability to many other scientific and industrial branches as, e.g., the seismic survey used in studies of geothermal aquifers. The following paper presents the opportunities provided by seismic methods applied to studies of geothermal resources in the central Poland where the geothermal waters are reservoired in both the Lower Cretaceous and the Lower Jurassic sedimentary successions. The presented results are obtained from a network of seismic profiles. An important advantage of the seismic survey is that they may support the selection of an optimal location of geothermal investment and determination of the geometry of geothermal aquifer. Furthermore, the application of geophysical methods can significantly contribute to the reduction of estimation error of groundwater reservoir temperature.

scholarly journals Role of multiple reflections in the formationof wave field in the cretaceous successions of the Middli Kura depression in Azerbaijan

2021 ◽  
Vol 43 (3) ◽  
pp. 123-134
Author(s):  
T. R. Akhmedov ◽  
T. Kh. Niyazov
Keyword(s):  
Wave Field ◽  
Upper Cretaceous ◽  
Oil And Gas ◽  
Geophysical Methods ◽  
Geological Structure ◽  
Gas Content ◽  
Seismic Exploration ◽  
Time Interval ◽  
Multiple Reflections ◽  
Seismic Sections

The article is devoted to the elucidation of the nature of the wave field recorded below the supporting-dominant seismic horizon «P» in the Middle Kura depression of Azerbaijan. A brief overview of the work carried out here is given; it is indicated that some geologists and geophysicists of our country, in our opinion, mistakenly assume that the observed wave field below the specified horizon is formed mainly by multiple reflections. Since the introduction of the common depth point method into the practice of seismic exploration, individual areas of the Middle Kura depression in Azerbaijan, including the Yevlakh-Agjabedi trough, have been repeatedly studied with varying degrees of frequency tracking. On the basis of this, a fairly large number of promising structures have been identified and mapped. But the structure of the Mesozoic, in particular the deposits of the Upper Cretaceous, still remains insufficiently studied. The study of the geological structure of the Mesozoic sediments, which are considered promising in terms of oil and gas content, is an urgent geological task; exploration work was carried out in the studied areas of the Middle Kura depression using a complex of geophysical methods at the modern technical and methodological level and new results were obtained. The constructed seismic sections show a dynamically pronounced and well-traceable seismic horizon corresponding to the Mesozoic surface and located deeper than it, relatively weak, short, discontinuous reflective boundaries that characterize the structure within the Mesozoic deposits. The studies carried out on the basis of modeling and velocity analysis made it possible to prove that the wave field in the time interval corresponding to the Mesozoic deposits owes its origin to intermittent single reflections from volcanic-carbonate deposits of the Upper Cretaceous age.

Source characteristics of earthquakes along the southern San Jacinto and Imperial fault zones (1937 to 1954)

1990 ◽  
Vol 80 (5) ◽  
pp. 1099-1117 ◽  
Author(s):  
Diane I. Doser
Keyword(s):  
Heat Flow ◽  
Source Parameters ◽  
Waveform Inversion ◽  
High Heat ◽  
Seismogenic Zone ◽  
Data Sets ◽  
Imperial Valley ◽  
Rupture Length ◽  
Lower Heat ◽  
Inversion Techniques

Abstract Body waveform inversion techniques are used to study the source parameters of four earthquakes occurring between 1937 and 1954 along the southern San Jacinto and Imperial faults (1937 Buck Ridge, 1940 Imperial Valley, 1942 Borrego Mountain, and 1954 Salada Wash events). All earthquakes had simple rupture histories with the exception of the 1940 Imperial Valley main shock, which consisted of at least four subevents whose relative locations indicate unilateral rupture toward the southeast. Earthquakes in regions of high heat flow (>80 mW/m2) had focal depths near the base of the seismogenic zone (8 to 10 km). The 1937 Buck Ridge earthquake, located in a region of lower heat flow, however, appears to have occurred at a shallow (3 ± 2 km) depth. The location, mechanism, and aftershock distribution for the 1942 Borrego Mountain earthquake suggest it could have occurred along the Split Mountain fault, a recently identified northeast-trending cross fault located between the Elsinore and Coyote Creek faults or along an unnamed fault that parallels the trend of the Coyote Creek fault. Moment and rupture length estimates obtained from this study agree well with estimates obtained in previous studies that used different data sets.

GEOPHYSICAL ACTIVITY IN 1976

Geophysics ◽  
1977 ◽  
Vol 42 (5) ◽  
pp. 1070-1084 ◽  
Author(s):  
H. R. Espey
Keyword(s):  
Geophysical Methods ◽  
Groundwater Exploration ◽  
Computer Processing ◽  
Petroleum Exploration ◽  
Government Agencies ◽  
Survey Questionnaire ◽  
Geothermal Exploration ◽  
Geophysical Techniques

This report provides statistics on worldwide use of geophysical methods in 1976. Data were obtained primarily through a survey questionnaire which was mailed out to more than 500 companies, government agencies, and universities that use geophysical techniques for petroleum exploration, oceanography, engineering, mining, geothermal exploration, and groundwater exploration. Response to the survey was excellent, providing detailed information on all types of airborne, land, and marine surveys. Computer processing was utilized in tabulating the statistics to provide detailed information on methods used, line‐miles covered, and average costs. Data not supplied on the questionnaire for costs or line‐mileage were estimated on the basis of worldwide averages to produce a more comprehensive report.

scholarly journals SEARCH FOR GEOTHERMAL SEISMIC NOISE IN THE EAST MESA AREA, IMPERIAL VALLEY, CALIFORNIA

Geophysics ◽  
1975 ◽  
Vol 40 (6) ◽  
pp. 1066-1072 ◽  
Author(s):  
H. M. Iyer
Keyword(s):  
Heat Flow ◽  
Seismic Noise ◽  
Critical Evaluation ◽  
Thermal Gradients ◽  
Noise Levels ◽  
Imperial Valley ◽  
Bureau Of Reclamation ◽  
Cultural Noise ◽  
Noise Experiment ◽  
The U.S

A seismic noise experiment was conducted in the East Mesa area of Imperial Valley, California, by the U.S. Geological Survey (USGS) in May 1972. There is a pronounced heat flow anomaly over the area, and between July 1972 and the present five deep test wells have been drilled over the anomaly by the U.S. Bureau of Reclamation (U.S. Bureau of Reclamation, 1974). At the time of our survey, we were aware of results from a preliminary seismic noise survey in East Mesa by Teledyne Geotech (Douze and Sorrells, 1972). A detailed noise survey was conducted by Teledyne Geotech soon after our experiment (Geothermal Staff of Teledyne Geotech, 1972). Both the Teledyne Geotech surveys show noise levels (in the 3.0 to 5.0 hz band) 12–18 db higher over the area where the thermal gradients and heat flow reach maximum values than in the surroundings. Our results, on the other hand, show that the seismic noise field in the area is dominated by cultural noise, and it is impossible to see a noise anomaly that can be related to the geothermal phenomena in East Mesa. We think that it is important to take into account this disagreement between the two results in order to make a critical evaluation of the utility of seismic noise as a geothermal prospecting tool. The purpose of this note is to put our findings on record.

Sign in / Sign up

Export Citation Format

Share Document