GEOTHERMAL GROUND‐NOISE SURVEYS

Geophysics ◽  
1972 ◽  
Vol 37 (5) ◽  
pp. 813-824 ◽  
Author(s):  
E. J. Douze ◽  
G. G. Sorrells
Keyword(s):  
Heat Flow ◽  
High Surface ◽  
Noise Levels ◽  
Imperial Valley ◽  
Geothermal Resources ◽  
Field Surveys ◽  
Short Period ◽  
Gravity Measurements ◽  
Ground Noise

In recent years there has been increasing interest in the role of geothermal steam as a source of energy. Only recently has geophysical exploration begun to play a major role in the exploration for geothermal resources; heat flow, gravity, and resistivity measurements have been the techniques most used. One recent development is the discovery that high surface‐noise levels are associated with the presence of geothermal reservoirs below the surface. Field surveys using short‐period seismographs have been conducted in the Imperial Valley of California in areas where heatflow measurements or drilling have indicated the presence of a geothermal deposit. In all three surveys abnormally high noise levels were found above the reservoir in the frequency range of 0.5 to 5.0 hz. The ground‐noise anomalies show a more complex pattern than the associated heat flow and gravity measurements. A theoretical model has been developed in which small, random pressure variations in a convecting geothermal reservoir are suggested as the source of the noise. Using this model, the noise level above one of the anomalies was duplicated, using a reasonably sized reservoir with pressure variations of less than 1 millibar.

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.

TESTS OF AN AIRBORNE GRAVITY METER

Geophysics ◽  
1960 ◽  
Vol 25 (1) ◽  
pp. 181-202 ◽  
Author(s):  
L. L. Nettleton ◽  
Lucien LaCoste ◽  
J. C. Harrison
Keyword(s):  
Airborne Gravity ◽  
Time Interval ◽  
Radar Altimeter ◽  
Imperial Valley ◽  
Contour Map ◽  
Surface Ship ◽  
Short Period ◽  
Gravity Measurements ◽  
Free Air Gravity ◽  
Averaging Time

Gravity measurements have been made in an airplane and a contour map using 20 mg interval constructed for 12,000 ft elevation. The LaCoste and Romberg instrument used is similar to that recently tested on a surface ship. The meter was installed in a B-17 aircraft equipped with APR (precision radar altimeter) and aerial mapping cameras for the accurate navigation needed for determination of the centrifugal (Eötvös) and elevation corrections. A series of nine lines over the Imperial Valley gave results believed to be accurate to about 10 mg or better as indicated by (1) the general consistency of the contour map and its similarity to a free air gravity map drawn from ground data, (2) repeat observations over almost the same courses, (3) agreement of independent values at line crossings (with Eötvös correction differences of as much as 2,000 mg), and (4) agreement with values calculated from ground gravity stations. Short period disturbances due to accelerations of the airplane are averaged over a certain time interval. This results in an “uncertainty principle,” in that the accuracy of observation increases as this time interval is lengthened, but details of the gravity variation are lost due to the increased distance traveled during each measurement. The values reported are for an averaging time of approximately three minutes corresponding to a travel distance of about ten miles. The quality of the results is adequate for geodetic purposes and possibly for certain regional geophysical problems.

scholarly journals The December 2018 Anak Krakatau Volcano Tsunami as Inferred from Post-Tsunami Field Surveys and Spectral Analysis

2019 ◽  
Vol 176 (12) ◽  
pp. 5219-5233 ◽  
Author(s):  
Abdul Muhari ◽  
Mohammad Heidarzadeh ◽  
Harjo Susmoro ◽  
Haris D. Nugroho ◽  
Estu Kriswati ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Tide Gauge ◽  
Small Islands ◽  
Tsunami Height ◽  
Tide Gauge Records ◽  
Field Surveys ◽  
Short Period ◽  
Dominant Period ◽  
Krakatau Volcano

AbstractWe present analysis of the December 2018 Anak Krakatau tsunami in Sunda Strait, Indonesia, from a combination of post-tsunami field surveys, bathymetric changes and spectral analysis of the tsunami tide gauge records. Post-tsunami surveys revealed moderate tsunami height along the coast of Sumatra and Java with maximum surveyed runup of 13.5 m and maximum inundation distance of 330 m. At small islands located close to the volcano, extreme tsunami impacts were observed indicating not only a huge tsunami was generated by large amounts of collapse material which caused notable changes of seafloor bathymetry, but also indicates the role of those small islands in reducing tsunami height that propagated to the mainland of Indonesia. Our spectral analysis of tide gauge records showed that the tsunami’s dominant period was 6.6–7.4 min, indicating the short-period nature of the 2018 Sunda Strait tsunami.

Coronary Intervention with the Excimer Laser: Review of the Technology and Outcome Data

2016 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
John Rawlins ◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Excimer Laser ◽  
Coronary Intervention ◽  
Outcome Data ◽  
Boston Scientific ◽  
Technical Aspects ◽  
Safety And Efficacy ◽  
Percutaneous Coronary ◽  
Short Period ◽  
Complex Lesions

Excimer laser coronary atherectomy (ELCA) is a long-established adjunctive therapy that can be applied during percutaneous coronary intervention (PCI). Technical aspects have evolved and there is an established safety and efficacy record across a number of clinical indications in contemporary interventional practice where complex lesions are routinely encountered. The role of ELCA during PCI for thrombus, non-crossable or non-expandable lesions, chronic occlusions and stent under-expansion are discussed in this review. The key advantage of ELCA over alternative atherectomy interventions is delivery on a standard 0.014-inch guidewire. Additionally, the technique can be mastered by any operator after a short period of training. The major limitation is presence of heavy calcification although when rotational atherectomy (RA) is required but cannot be applied due to inability to deliver the dedicated RotaWire™ (Boston Scientific), ELCA can create an upstream channel to permit RotaWire passage and complete the case with RA – the RASER technique.

scholarly journals The Role of Technology in Greenhouse Agriculture: Towards a Sustainable Intensification in Campo de Dalías (Almería, Spain)

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 101
Author(s):  
Antonio J. Mendoza-Fernández ◽  
Araceli Peña-Fernández ◽  
Luis Molina ◽  
Pedro A. Aguilera
Keyword(s):  
Land Use ◽  
Economic Development ◽  
Water Resources ◽  
Natural Resources ◽  
Temporal Evolution ◽  
Technological Development ◽  
Sustainable Intensification ◽  
Short Period ◽  
Cultivation Techniques

Campo de Dalías, located in southeastern Spain, is the greatest European exponent of greenhouse agriculture. The development of this type of agriculture has led to an exponential economic development of one of the poorest areas of Spain, in a short period of time. Simultaneously, it has brought about a serious alteration of natural resources. This article will study the temporal evolution of changes in land use, and the exploitation of groundwater. Likewise, this study will delve into the technological development in greenhouses (irrigation techniques, new water resources, greenhouse structures or improvement in cultivation techniques) seeking a sustainable intensification of agriculture under plastic. This sustainable intensification also implies the conservation of existing natural areas.

scholarly journals Potential Role of Vitamins and Zinc on Acute Respiratory Infections Including Covid-19

2021 ◽  
Vol 8 ◽  
pp. 2333794X2110217
Author(s):  
Indah K. Murni ◽  
Endy P. Prawirohartono ◽  
Rina Triasih
Keyword(s):  
Vitamin A ◽  
Vitamin C ◽  
Large Dose ◽  
Common Cold ◽  
Potential Role ◽  
Respiratory Infections ◽  
Acute Respiratory Infections ◽  
Under Five ◽  
Short Period

Background. Vitamin C, E, D, A, zinc are considered to be essential in preventing and treating of acute respiratory infections (ARI) including COVID-19. Methods. We reviewed published studies evaluating the potential roles of these vitamin and zinc for ARIs and COVID-19 using Medline database, medRxiv, and bibliographic references. Results. Vitamins C, D, and E did not reduce incidence of common cold in general, but vitamin C reduced by half in population with physical and environment stresses. Vitamins C and E shortened duration and reduced severity of common cold. A large-dose vitamin A had no effect on recovery from pneumonia. Zinc improved clinical deterioration and pneumonia duration in under five. The effect on preventing COVID-19 morbidity and related-death was lacking. Conclusions. Although the effects of vitamins and zinc on ARIs including COVID-19 were inconclusive, taking these for a short period during pandemic may be beneficial when there is risks of deficiency.

scholarly journals Single and Dual Metal Oxides as Promising Supports for Carbon Monoxide Removal from an Actual Syngas: The Crucial Role of Support on the Selectivity of the Au–Cu System

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 852 ◽  
Author(s):  
Bernay Cifuentes ◽  
Felipe Bustamante ◽  
Martha Cobo
Keyword(s):  
Metal Oxides ◽  
High Surface ◽  
High Surface Area ◽  
Carbon Deposits ◽  
Promising Strategy ◽  
Cu Catalysts ◽  
Dual Metal ◽  
Effect Of The Support ◽  
Lower Capacity

A catalytic screening was performed to determine the effect of the support on the performance of an Au–Cu based system for the removal of CO from an actual syngas. First, a syngas was obtained from reforming of ethanol. Then, the reformer outlet was connected to a second reactor, where Au–Cu catalysts supported on several single and dual metal oxides (i.e., CeO2, SiO2, ZrO2, Al2O3, La2O3, Fe2O3, CeO2-SiO2, CeO2-ZrO2, and CeO2-Al2O3) were evaluated. AuCu/CeO2 was the most active catalyst due to an elevated oxygen mobility over the surface, promoting CO2 formation from adsorption of C–O* and OH− intermediates on Au0 and CuO species. However, its lower capacity to release the surface oxygen contributes to the generation of stable carbon deposits, which lead to its rapid deactivation. On the other hand, AuCu/CeO2-SiO2 was more stable due to its high surface area and lower formation of formate and carbonate intermediates, mitigating carbon deposits. Therefore, use of dual supports could be a promising strategy to overcome the low stability of AuCu/CeO2. The results of this research are a contribution to integrated production and purification of H2 in a compact system.

scholarly journals Springtime high surface ozone events over the western United States: Quantifying the role of stratospheric intrusions

2012 ◽  
Vol 117 (D21) ◽  
pp. n/a-n/a ◽  
Author(s):  
Meiyun Lin ◽  
Arlene M. Fiore ◽  
Owen R. Cooper ◽  
Larry W. Horowitz ◽  
Andrew O. Langford ◽  
...  
Keyword(s):  
United States ◽  
Surface Ozone ◽  
High Surface ◽  
Western United States ◽  
Stratospheric Intrusions

Heat flow and geothermal resources in northern Italy

2014 ◽  
Vol 36 ◽  
pp. 277-285 ◽  
Author(s):  
V. Pasquale ◽  
M. Verdoya ◽  
P. Chiozzi
Keyword(s):  
Heat Flow ◽  
Northern Italy ◽  
Geothermal Resources
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