Ivan Wong - Academia.edu (original) (raw)

Papers by Ivan Wong

Strong earthquake ground motions have been estimated for ten sites at the Idaho National Engineer... more Strong earthquake ground motions have been estimated for ten sites at the Idaho National Engineering Laboratory assuming that an event similar to the 1983 M{sub s} 7.3 Borah Peak earthquake occurs along the southern segment of the Lemhi fault. The strong ground motion parameters have been estimated based on a methodology incorporating the Band-Limited-White-Noise ground motion model coupled with Random Vibration Theory. A 16-station seismic attenuation and site response survey utilizing three-component portable digital seismographs was also performed for a five-month period in 1989. Based on strong motion records of the 1983 Borah Peak earthquake and recordings of other regional earthquakes, the seismic attenuation in the shallow crust (κ) and local site response have been evaluated. These data combined with detailed geologic profiles developed for each site based principally on borehole data, were used in the estimation of the strong ground motion parameters. The peak horizontal ground accelerations for individual sites range from approximately 0.15 to 0.40 g at distances of 27 to 11 km. Based on our analysis, the thicker sedimentary interbeds in the basalt section attenuate high frequency ground motions. 22 refs., 5 figs.

As the global demand for energy increases, the contribution from geothermal energy could be extre... more As the global demand for energy increases, the contribution from geothermal energy could be extremely large, particularly if resources developed with enhanced geothermal systems (EGS) technology are incorporated into the total energy picture. A recent study by MIT (2006) predicts that in the U.S. alone, 100,000 MWe of cost-competitive capacity could be provided by EGS in the next 50 years with reasonable investment. The U.S. Geological Survey estimates that in the U.S., which uses about 100 quads of energy per year, there are 300,000 quads in the >200°C heat sources down to 6 km depth. Other large countries, such as India and China, have similar heat resources, so the global potential of geothermal energy is enormous, if EGS can be developed on a large scale.

The Lemhi fault is a 140-km-long range-bounding normal fault in the northern Basin and Range prov... more The Lemhi fault is a 140-km-long range-bounding normal fault in the northern Basin and Range province, north of the eastern Snake River Plain (ESRP). The authors investigation of the southern two (proposed) rupture segments, the Howe and the Fallert Springs, to the north, identified multiple large late Quaternary, surface-faulting events, some of which occurred in temporal clusters. Geologic evidence suggest

2005 Salt Lake City Annual Meeting (October 16–19, 2005). Paper No. 24-13, Presentation Time: 11:... more 2005 Salt Lake City Annual Meeting (October 16–19, 2005). Paper No. 24-13, Presentation Time: 11:15 AM-11:30 AM. SEISMOTECTONICS AND STRESS FIELD OF THE TETON FAULT AND INTERACTIONS WITH THE YELLOWSTONE ...

... Jawhar Bouabid 1 , Ivan Wong 2 , Gilles Bureau 3 , William Graf 4 , Charles Huyck 5 , Allan P... more ... Jawhar Bouabid 1 , Ivan Wong 2 , Gilles Bureau 3 , William Graf 4 , Charles Huyck 5 , Allan Porush 6 , Timothy Siegel 7 , Walter Silva 8 , Michael Swigart 9 , Ronald Eguchi 10 , Jeff Rouleau 11 , John Knight 12 , and Tammie Dreher 13 ... Aiken Oconee Pickens Greenville ...

The occurrence of the 1882 M 6.6 earthquake suggests that there may be a significant, albeit poor... more The occurrence of the 1882 M 6.6 earthquake suggests that there may be a significant, albeit poorly quantified, seismic hazard in the Front Range of Colorado. In an effort to better characterize this hazard in the central Front Range, we have used a joint hypocenter-velocity inversion to improve hypocentral locations and derive a velocity model from a well-recorded set of microearthquakes (Richter magnitude [M L ] ≤ 3.3). The dataset consists of more than 1,100 events recorded by Microgeophysics Corporation (MGC) from 1983 to 1993 for the Denver Water Department. About 50 stations from the MGC network were used in this study. A 1D joint hypocenter-velocity inversion was first used to find the best estimate 1D velocity model for the region and the dataset. These results were then used as a starting model for a 3D inversion. long recurrence intervals of several tens of thousands to more than 100,000 years, or (3) the Miocene and younger faults are not seismogenic and that earthquakes like 1882 occur on buried or yet undiscovered faults.

Minerva Ortopedica e Traumatologica

Femoral acetabular impingement (FAI) is a recently proposed mechanism causing an abnormal contact... more Femoral acetabular impingement (FAI) is a recently proposed mechanism causing an abnormal contact between femur and acetabulum, resulting in labral and articular cartilage damage around the hip. In the majority of cases, a bony or cartilaginous deformity of the femoral neck, acetabulum, or both cause FAI. Recent interest in FAI resulted from evidence that suggest FAI may lead to early arthritis of the hip. Advances in arthroscopy in the hip have allowed for instrumentation and techniques to treat FAI and early results are promising. Early recognition of FAI followed by subsequent behavioral modification (profession, sports, etc.) or even surgery may reduce the rate of osteoarthritis (OA) due to FAI.

Quaternary faults in the central Rocky Mountain of CO exhibit normal displacement, are generally ... more Quaternary faults in the central Rocky Mountain of CO exhibit normal displacement, are generally parallel to the strike of pre-existing Larmide structures, and typically occur in the hanging walls of Laramide thrust faults. These observations are consistent with models in which Mesozoic thrust faults are being reactivated as normal faults in the contemporary extensional tectonic setting. To assess the seismogenic potential of these faults, the authors evaluated the recency of fault movement and style of deformation via aerial reconnaissance, interpretation of aerial photography and field mapping of selected sites. The 82-km-long Red Rocks-Climarron fault zone shows evidence of late Quaternary displacement and may be capable of producing an M[>=]6.75 earthquake based on its total fault length and inferred fault width. Earthquake hypocenters indicate that the thickness of the seismogence crust in CO is similar to much of the western US (ca. 15 km). In additional to tectonic deforma...

Typically the largest source of uncertainty in estimating earthquake ground shaking at a site are... more Typically the largest source of uncertainty in estimating earthquake ground shaking at a site are the ground motion predictive equations. Until recently, these equations or models for the western U.S. for large earthquakes (moment magnitude [M] > 7) at close-in distances (< 20 km) were based on a sparse database of strong motion recordings. Unfortunately, large earthquakes at relatively short distances are the events of most engineering relevance to a majority of dams in the seismically active portions of the western U.S. State-of-the-art ground motion equations have been recently developed as part of the Pacific Earthquake Engineering Research (PEER) Center's Next Generation of Attenuation (NGA) Project. These new models have benefited from a significantly enhanced database of near-field strong motion records of earthquakes such as the 1999 M 7.6 Chi Chi, Taiwan, 1999 M 7.4 Kocaeli and M 7.1 Duzce, Turkey, and 2002 M 7.9 Denali, Alaska events. The NGA models predict ground motions that are significantly lower than previous models for large earthquakes, and hence there could be a significant impact on past and current assessments of seismic hazards of western U.S. dams. In the past decade using pre-NGA models, we have evaluated the seismic hazards of nearly 200 dams in the western U.S., the majority for the U.S. Bureau of Reclamation. In this study, we have updated the probabilistic seismic hazard of 20 dams distributed throughout the western U.S. to evaluate the impact of the NGA models. Based on our analyses, the impact will be significant for many western U.S. dams and will pose questions of acceptability, both technical and political, to dam regulatory agencies.

As demonstrated in the 2006 M 6.7 Kiholo Bay earthquake, where some strong motion stations record... more As demonstrated in the 2006 M 6.7 Kiholo Bay earthquake, where some strong motion stations recorded peak horizontal accelerations close to 1g, site response effects can be significant on the Big Island. As part of FEMA-supported studies following the earthquake, we have produced a new 1:100,000-scale map of site conditions for the Big Island of Hawaii. The mapping makes use of about 25 new SASW measurements (Wong et al., 2008) and 1:100,000-scale geologic mapping by Sherrod et al. (2007). An earlier 2006 site class map portrayed nearly all of the island as NEHRP site class B; however, based on about 20 SASW measurements in areas mapped as basalt, we believe that most of the island should be mapped as NEHRP C or D. Vs30 estimates for these basalt sites ranged from 844 to 1,812 ft/sec, spanning NEHRP classes C and D. The median value for these Vs30 estimates is 1,304 ft/sec, with a log mean of 1,274 ft/sec and a standard deviation of 274 ft/sec. The sites cover a range of basaltic roc...

ABSTRACT As part of a study to characterize the seismic hazards along the populated Wasatch Front... more ABSTRACT As part of a study to characterize the seismic hazards along the populated Wasatch Front extending from Ogden south to Provo, including the Salt Lake City metropolitan area, we have developed three ground shaking hazard microzonation maps. ...

In the past two decades, a tremendous amount of new information and data has emerged on seismic s... more In the past two decades, a tremendous amount of new information and data has emerged on seismic sources in the Intermountain United States and their associated processes of earthquake generation. Consequently, the seismic safety of U.S. uranium mill tailings sites, which are located almost exclusively in this region, are being reviewed by the U.S. Nuclear Regulatory Commission (NRC). Based on a deterministic and probabilistic re-evaluation of potential seismic hazards at a Title II site in southeastern Utah, three significant issues have been raised which will impact other sites in the Intermountain U.S. required to revisit their seismic design criteria by the NRC. These issues are: (1) whether the NRC's required use of a deterministic approach for assessing seismic hazards is appropriate for Title II uranium mill tailings sites in a region such as the Intermountain U.S.; (2) is the alternative approach of probabilistic seismic hazard analysis acceptable to the NRC for uranium m...

ABSTRACT Podium Presentation

Strong earthquake ground motions have been estimated for ten sites at the Idaho National Engineer... more Strong earthquake ground motions have been estimated for ten sites at the Idaho National Engineering Laboratory assuming that an event similar to the 1983 M{sub s} 7.3 Borah Peak earthquake occurs along the southern segment of the Lemhi fault. The strong ground motion parameters have been estimated based on a methodology incorporating the Band-Limited-White-Noise ground motion model coupled with Random Vibration Theory. A 16-station seismic attenuation and site response survey utilizing three-component portable digital seismographs was also performed for a five-month period in 1989. Based on strong motion records of the 1983 Borah Peak earthquake and recordings of other regional earthquakes, the seismic attenuation in the shallow crust (κ) and local site response have been evaluated. These data combined with detailed geologic profiles developed for each site based principally on borehole data, were used in the estimation of the strong ground motion parameters. The peak horizontal ground accelerations for individual sites range from approximately 0.15 to 0.40 g at distances of 27 to 11 km. Based on our analysis, the thicker sedimentary interbeds in the basalt section attenuate high frequency ground motions. 22 refs., 5 figs.

As the global demand for energy increases, the contribution from geothermal energy could be extre... more As the global demand for energy increases, the contribution from geothermal energy could be extremely large, particularly if resources developed with enhanced geothermal systems (EGS) technology are incorporated into the total energy picture. A recent study by MIT (2006) predicts that in the U.S. alone, 100,000 MWe of cost-competitive capacity could be provided by EGS in the next 50 years with reasonable investment. The U.S. Geological Survey estimates that in the U.S., which uses about 100 quads of energy per year, there are 300,000 quads in the >200°C heat sources down to 6 km depth. Other large countries, such as India and China, have similar heat resources, so the global potential of geothermal energy is enormous, if EGS can be developed on a large scale.

The Lemhi fault is a 140-km-long range-bounding normal fault in the northern Basin and Range prov... more The Lemhi fault is a 140-km-long range-bounding normal fault in the northern Basin and Range province, north of the eastern Snake River Plain (ESRP). The authors investigation of the southern two (proposed) rupture segments, the Howe and the Fallert Springs, to the north, identified multiple large late Quaternary, surface-faulting events, some of which occurred in temporal clusters. Geologic evidence suggest

2005 Salt Lake City Annual Meeting (October 16–19, 2005). Paper No. 24-13, Presentation Time: 11:... more 2005 Salt Lake City Annual Meeting (October 16–19, 2005). Paper No. 24-13, Presentation Time: 11:15 AM-11:30 AM. SEISMOTECTONICS AND STRESS FIELD OF THE TETON FAULT AND INTERACTIONS WITH THE YELLOWSTONE ...

... Jawhar Bouabid 1 , Ivan Wong 2 , Gilles Bureau 3 , William Graf 4 , Charles Huyck 5 , Allan P... more ... Jawhar Bouabid 1 , Ivan Wong 2 , Gilles Bureau 3 , William Graf 4 , Charles Huyck 5 , Allan Porush 6 , Timothy Siegel 7 , Walter Silva 8 , Michael Swigart 9 , Ronald Eguchi 10 , Jeff Rouleau 11 , John Knight 12 , and Tammie Dreher 13 ... Aiken Oconee Pickens Greenville ...

The occurrence of the 1882 M 6.6 earthquake suggests that there may be a significant, albeit poor... more The occurrence of the 1882 M 6.6 earthquake suggests that there may be a significant, albeit poorly quantified, seismic hazard in the Front Range of Colorado. In an effort to better characterize this hazard in the central Front Range, we have used a joint hypocenter-velocity inversion to improve hypocentral locations and derive a velocity model from a well-recorded set of microearthquakes (Richter magnitude [M L ] ≤ 3.3). The dataset consists of more than 1,100 events recorded by Microgeophysics Corporation (MGC) from 1983 to 1993 for the Denver Water Department. About 50 stations from the MGC network were used in this study. A 1D joint hypocenter-velocity inversion was first used to find the best estimate 1D velocity model for the region and the dataset. These results were then used as a starting model for a 3D inversion. long recurrence intervals of several tens of thousands to more than 100,000 years, or (3) the Miocene and younger faults are not seismogenic and that earthquakes like 1882 occur on buried or yet undiscovered faults.

Minerva Ortopedica e Traumatologica

Femoral acetabular impingement (FAI) is a recently proposed mechanism causing an abnormal contact... more Femoral acetabular impingement (FAI) is a recently proposed mechanism causing an abnormal contact between femur and acetabulum, resulting in labral and articular cartilage damage around the hip. In the majority of cases, a bony or cartilaginous deformity of the femoral neck, acetabulum, or both cause FAI. Recent interest in FAI resulted from evidence that suggest FAI may lead to early arthritis of the hip. Advances in arthroscopy in the hip have allowed for instrumentation and techniques to treat FAI and early results are promising. Early recognition of FAI followed by subsequent behavioral modification (profession, sports, etc.) or even surgery may reduce the rate of osteoarthritis (OA) due to FAI.

Quaternary faults in the central Rocky Mountain of CO exhibit normal displacement, are generally ... more Quaternary faults in the central Rocky Mountain of CO exhibit normal displacement, are generally parallel to the strike of pre-existing Larmide structures, and typically occur in the hanging walls of Laramide thrust faults. These observations are consistent with models in which Mesozoic thrust faults are being reactivated as normal faults in the contemporary extensional tectonic setting. To assess the seismogenic potential of these faults, the authors evaluated the recency of fault movement and style of deformation via aerial reconnaissance, interpretation of aerial photography and field mapping of selected sites. The 82-km-long Red Rocks-Climarron fault zone shows evidence of late Quaternary displacement and may be capable of producing an M[>=]6.75 earthquake based on its total fault length and inferred fault width. Earthquake hypocenters indicate that the thickness of the seismogence crust in CO is similar to much of the western US (ca. 15 km). In additional to tectonic deforma...

Typically the largest source of uncertainty in estimating earthquake ground shaking at a site are... more Typically the largest source of uncertainty in estimating earthquake ground shaking at a site are the ground motion predictive equations. Until recently, these equations or models for the western U.S. for large earthquakes (moment magnitude [M] > 7) at close-in distances (< 20 km) were based on a sparse database of strong motion recordings. Unfortunately, large earthquakes at relatively short distances are the events of most engineering relevance to a majority of dams in the seismically active portions of the western U.S. State-of-the-art ground motion equations have been recently developed as part of the Pacific Earthquake Engineering Research (PEER) Center's Next Generation of Attenuation (NGA) Project. These new models have benefited from a significantly enhanced database of near-field strong motion records of earthquakes such as the 1999 M 7.6 Chi Chi, Taiwan, 1999 M 7.4 Kocaeli and M 7.1 Duzce, Turkey, and 2002 M 7.9 Denali, Alaska events. The NGA models predict ground motions that are significantly lower than previous models for large earthquakes, and hence there could be a significant impact on past and current assessments of seismic hazards of western U.S. dams. In the past decade using pre-NGA models, we have evaluated the seismic hazards of nearly 200 dams in the western U.S., the majority for the U.S. Bureau of Reclamation. In this study, we have updated the probabilistic seismic hazard of 20 dams distributed throughout the western U.S. to evaluate the impact of the NGA models. Based on our analyses, the impact will be significant for many western U.S. dams and will pose questions of acceptability, both technical and political, to dam regulatory agencies.

As demonstrated in the 2006 M 6.7 Kiholo Bay earthquake, where some strong motion stations record... more As demonstrated in the 2006 M 6.7 Kiholo Bay earthquake, where some strong motion stations recorded peak horizontal accelerations close to 1g, site response effects can be significant on the Big Island. As part of FEMA-supported studies following the earthquake, we have produced a new 1:100,000-scale map of site conditions for the Big Island of Hawaii. The mapping makes use of about 25 new SASW measurements (Wong et al., 2008) and 1:100,000-scale geologic mapping by Sherrod et al. (2007). An earlier 2006 site class map portrayed nearly all of the island as NEHRP site class B; however, based on about 20 SASW measurements in areas mapped as basalt, we believe that most of the island should be mapped as NEHRP C or D. Vs30 estimates for these basalt sites ranged from 844 to 1,812 ft/sec, spanning NEHRP classes C and D. The median value for these Vs30 estimates is 1,304 ft/sec, with a log mean of 1,274 ft/sec and a standard deviation of 274 ft/sec. The sites cover a range of basaltic roc...

ABSTRACT As part of a study to characterize the seismic hazards along the populated Wasatch Front... more ABSTRACT As part of a study to characterize the seismic hazards along the populated Wasatch Front extending from Ogden south to Provo, including the Salt Lake City metropolitan area, we have developed three ground shaking hazard microzonation maps. ...

In the past two decades, a tremendous amount of new information and data has emerged on seismic s... more In the past two decades, a tremendous amount of new information and data has emerged on seismic sources in the Intermountain United States and their associated processes of earthquake generation. Consequently, the seismic safety of U.S. uranium mill tailings sites, which are located almost exclusively in this region, are being reviewed by the U.S. Nuclear Regulatory Commission (NRC). Based on a deterministic and probabilistic re-evaluation of potential seismic hazards at a Title II site in southeastern Utah, three significant issues have been raised which will impact other sites in the Intermountain U.S. required to revisit their seismic design criteria by the NRC. These issues are: (1) whether the NRC's required use of a deterministic approach for assessing seismic hazards is appropriate for Title II uranium mill tailings sites in a region such as the Intermountain U.S.; (2) is the alternative approach of probabilistic seismic hazard analysis acceptable to the NRC for uranium m...

ABSTRACT Podium Presentation