scholarly journals Apparent break in earthquake scaling due to path and site effects on deep borehole recordings

2003 ◽  
Vol 108 (B5) ◽  
Author(s):  
Satoshi Ide ◽  
Gregory C. Beroza ◽  
Stephanie G. Prejean ◽  
William L. Ellsworth
Keyword(s):  
Site Effects ◽  
Deep Borehole ◽  
Earthquake Scaling

Reliable and economical high-temperature deep-borehole seismic recording

1996 ◽  
Vol 86 (1A) ◽  
pp. 204-211
Author(s):  
Derek V. Manov ◽  
Rachel E. Abercrombie ◽  
Peter C. Leary
Keyword(s):  
Site Effects ◽  
Oil Well ◽  
Deep Borehole ◽  
Reliable System ◽  
Active Sensors ◽  
Near Surface ◽  
Active Tectonic ◽  
Seismic Recording ◽  
Source Scaling ◽  
Borehole Seismic

Abstract Recording earthquakes with borehole seismometers has become increasingly popular in recent years as the advantages in noise reduction and also the distorting effects of near-surface rocks, especially sediments, have become well known. Borehole recording can be extremely complex, involving active sensors, special cables, and downhole electronics. Such installations, however, are often not very reliable at the high temperatures reached in active tectonic areas at depths of 1 km and greater. Here we describe a simple and reliable system for 3-component recording of local earthquakes at single and multiple depths greater than 1.5 km and temperatures up to 120°C. Our system was designed and developed for experiments in the Cajon Pass Scientific Drillhole of Southern California. The borehole packages are made of titanium with spring-loaded clamping, allowing easy retrieval. Standard seven-conductor oil-well logging cables are used together with a specially designed cablehead. The data recorded have been used for investigating earthquake source scaling, attenuation in the mid-crust, and also near-surface site effects.

Regionally continuous Miocene rhyolites beneath the eastern Snake River Plain reveal localized flexure at its western margin: Idaho National Laboratory and vicinity

2020 ◽  
Vol 57 (3) ◽  
pp. 241-270
Author(s):  
Kyle L. Schusler ◽  
David M. Pearson ◽  
Michael McCurry ◽  
Roy C. Bartholomay ◽  
Mark H. Anders
Keyword(s):  
Volcanic Rocks ◽  
Snake River Plain ◽  
North American Plate ◽  
Snake River ◽  
Trace Element Geochemistry ◽  
Deep Borehole ◽  
Age Progression ◽  
Western Margin ◽  
Silicic Volcanic ◽  
River Plain

The eastern Snake River Plain (ESRP) is a northeast-trending topographic basin interpreted to be the result of the time-transgressive track of the North American plate above the Yellowstone hotspot. The track is defined by the age progression of silicic volcanic rocks exposed along the margins of the ESRP. However, the bulk of these silicic rocks are buried under 1 to 3 kilometers of younger basalts. Here, silicic volcanic rocks recovered from boreholes that penetrate below the basalts, including INEL-1, WO-2 and new deep borehole USGS-142, are correlated with one another and to surface exposures to assess various models for ESRP subsidence. These correlations are established on U/Pb zircon and 40Ar/39Ar sanidine age determinations, phenocryst assemblages, major and trace element geochemistry, δ18O isotopic data from selected phenocrysts, and initial εHf values of zircon. These data suggest a correlation of: (1) the newly documented 8.1 ± 0.2 Ma rhyolite of Butte Quarry (sample 17KS03), exposed near Arco, Idaho to the upper-most Picabo volcanic field rhyolites found in borehole INEL-1; (2) the 6.73 ± 0.02 Ma East Arco Hills rhyolite (sample 16KS02) to the Blacktail Creek Tuff, which was also encountered at the bottom of borehole WO-2; and (3) the 6.42 ± 0.07 Ma rhyolite of borehole USGS-142 to the Walcott Tuff B encountered in deep borehole WO-2. These results show that rhyolites found along the western margin of the ESRP dip ~20º south-southeast toward the basin axis, and then gradually tilt less steeply in the subsurface as the axis is approached. This subsurface pattern of tilting is consistent with a previously proposed crustal flexural model of subsidence based only on surface exposures, but is inconsistent with subsidence models that require accommodation of ESRP subsidence on either a major normal fault or strike-slip fault.

Site effects of the Denis-Perron dam (SM-3): A case study in Eastern North America

2021 ◽  
pp. 875529302110194
Author(s):  
Daniel Verret ◽  
Denis LeBœuf ◽  
Éric Péloquin
Keyword(s):  
North America ◽  
Ground Motion ◽  
Site Effects ◽  
Transfer Functions ◽  
Ground Motions ◽  
Published Data ◽  
Eastern North America ◽  
Ground Acceleration ◽  
Large Dams ◽  
Moderate Seismicity

Eastern North America (ENA) is part of a region with low-to-moderate seismicity; nonetheless, some significant seismic events have occurred in the last few decades. Recent events have reemphasized the need to review ENA seismicity and ground motion models, along with continually reevaluating and updating procedures related to the seismic safety assessment of hydroelectric infrastructures, particularly large dams in Québec. Furthermore, recent researchers have shown that site-specific characteristics, topography, and valley shapes may significantly aggravate the severity of ground motions. To the best of our knowledge, very few instrumental data from actual earthquakes have been published for examining the site effects of hydroelectric dam structures located in eastern Canada. This article presents an analysis of three small earthquakes that occurred in 1999 and 2002 at the Denis-Perron (SM-3) dam. This dam, the highest in Québec, is a rockfill embankment structure with a height of 171 m and a length of 378 m; it is located in a narrow valley. The ground motion datasets of these earthquakes include the bedrock and dam crest three-component accelerometer recordings. Ground motions are analyzed both in the time and frequency domains. The spectral ratios and transfer functions obtained from these small earthquakes provide new insights into the directionality of resonant frequencies, vibration modes, and site effects for the Denis-Perron dam. The crest amplifications observed for this dam are also compared with previously published data for large dams. New statistical relationships are proposed to establish dam crest amplification on the basis of the peak ground acceleration (PGA) at the foundation.

scholarly journals Modelling an unconventional closed-loop deep borehole heat exchanger (DBHE): sensitivity analysis on the Newberry volcanic setting

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannah R. Doran ◽  
Theo Renaud ◽  
Gioia Falcone ◽  
Lehua Pan ◽  
Patrick G. Verdin
Keyword(s):  
Sensitivity Analysis ◽  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Energy Flow ◽  
Closed Loop ◽  
Working Fluid ◽  
Valuable Insight ◽  
Deep Borehole

AbstractAlternative (unconventional) deep geothermal designs are needed to provide a secure and efficient geothermal energy supply. An in-depth sensitivity analysis was investigated considering a deep borehole closed-loop heat exchanger (DBHE) to overcome the current limitations of deep EGS. A T2Well/EOS1 model previously calibrated on an experimental DBHE in Hawaii was adapted to the current NWG 55-29 well at the Newberry volcano site in Central Oregon. A sensitivity analysis was carried out, including parameters such as the working fluid mass flow rate, the casing and cement thermal properties, and the wellbore radii dimensions. The results conclude the highest energy flow rate to be 1.5 MW, after an annulus radii increase and an imposed mass flow rate of 5 kg/s. At 3 kg/s, the DBHE yielded an energy flow rate a factor of 3.5 lower than the NWG 55-29 conventional design. Despite this loss, the sensitivity analysis allows an assessment of the key thermodynamics within the wellbore and provides a valuable insight into how heat is lost/gained throughout the system. This analysis was performed under the assumption of subcritical conditions, and could aid the development of unconventional designs within future EGS work like the Newberry Deep Drilling Project (NDDP). Requirements for further software development are briefly discussed, which would facilitate the modelling of unconventional geothermal wells in supercritical systems to support EGS projects that could extend to deeper depths.

In vitro comparison of harvesting site effects on cardiac extracellular matrix hydrogels

2021 ◽  
Author(s):  
Emily Mulvany ◽  
Sara McMahan ◽  
Jiazhu Xu ◽  
Narges Yazdani ◽  
Rebecca Willits ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Site Effects ◽  
In Vitro Comparison

Heat extraction model and characteristics of coaxial deep borehole heat exchanger

2021 ◽  
Vol 169 ◽  
pp. 738-751
Author(s):  
Ji Li ◽  
Wei Xu ◽  
Jianfeng Li ◽  
Shuai Huang ◽  
Zhao Li ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Extraction ◽  
Deep Borehole ◽  
Borehole Heat Exchanger ◽  
Extraction Model

scholarly journals Integrating climate, soil and stand structure into allometric models: An approach of site-effects on tree allometry in Atlantic Forest

2021 ◽  
Vol 127 ◽  
pp. 107794
Author(s):  
Vinicius Costa Cysneiros ◽  
Fernanda Coelho de Souza ◽  
Tatiana Dias Gaui ◽  
Allan Libanio Pelissari ◽  
Gabriel Agostini Orso ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Site Effects ◽  
Stand Structure ◽  
Tree Allometry ◽  
Allometric Models
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