Pilot Studies of Seismic Hazard and Risk in North Sulawesi Province, Indonesia

1993 ◽  
Vol 9 (1) ◽  
pp. 97-120
Author(s):  
Paul C. Thenhaus ◽  
Stanley L. Hanson ◽  
Ismet Effendi ◽  
Engkon K. Kertapati ◽  
S. T. Algermissen
Keyword(s):  
Subduction Zone ◽  
Ground Motions ◽  
Soft Soil ◽  
Strong Motion ◽  
The United States ◽  
Worst Case ◽  
Pilot Studies ◽  
Masonry Construction ◽  
North Sulawesi ◽  
Average Annual Loss

Earthquake ground motions in North Sulawesi on soft soil that have a 90 percent probability of not being exceeded in 50 years are estimated to be 0.63 g (63 percent of the acceleration of gravity) at Palu, 0.31 g at Gorontalo, and 0.27 g at Manado. Estimated ground motions for rock conditions for the same probability level and exposure time are 56 percent of those for soft soil. The hazard estimates are obtained from seismic sources that model the earthquake potential to a depth of 100 km beneath northern and central Sulawesi and include the Palu fault zone of western Sulawesi, the North Sulawesi subduction zone, and the southern most segment of the Sangihe subduction zone beneath the Molucca Sea. An attenuation relation based on Japanese strong-motion data and considered appropriate for subduction environments of the western Pacific was used in determination of ground motions. Field investigations following the 18 April 1990 North Sulawesi earthquake (Ms 7.3) established the Modified Mercalli intensity (MMI) distribution throughout Kodya Gorontalo (the mayorial province of Gorontalo). The total number of masonry houses (permanent and semipermanent dwellings) within the MMI V isoseismal was approximated from housing counts obtained from a sampling of 19 villages. From the post-earthquake damage investigation and from comparisons to masonry construction in the United States, a vulnerability curve was constructed for masonry housing in Gorontalo. Assuming an average value for a house of $1,053, total economic loss to masonry housing from the 18 April 1990 earthquake is estimated to be $1,198,578, a loss equivalent to the destruction of 9.6 percent of the masonry dwelling stock of Gorontalo. Simulation of the earthquake history for the past 31 years within 300 km of Gorontalo indicates an average annual loss to masonry housing of $358,609, or $30 on a per house basis. Catastrophe potential (a worst-case loss) for masonry housing in Gorontalo that has a 90 percent probability of not being exceeded in 250 years is estimated to be $3,083,525, a loss equivalent to the destruction of 25 percent of the masonry dwelling stock of Gorontalo.

Surface Motions on Near-Distance Rock Sites in the 2011 Tohoku-Oki Earthquake

2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 23-35 ◽  
Author(s):  
John G. Anderson
Keyword(s):  
Subduction Zone ◽  
Ground Motions ◽  
Source Parameters ◽  
Strong Motion ◽  
Tohoku Earthquake ◽  
Wide Range ◽  
Subduction Zone Earthquakes

This paper selects several sites intended to represent relatively undistorted rock motions just inland from the faulting in the 2011 Tohoku-oki earthquake. Sites were selected for relatively high values of VS30 and for absence of strong site resonances. At these sites, ground motions at the surface were moderate, with peak accelerations of up to ∼330 cm/s2 and peak velocities up to ∼45 cm/s. Although moderate, these records imply that the strong motion generating area of the Tohoku earthquake was as much as ten times more energetic than the 1985 Michoacan earthquake, for which ground motions on rock were recorded above a strong motion generating area. These results suggest that a wide range of source parameters can occur in subduction zone earthquakes.

Ground-motion model for subduction earthquakes in northern South America

2021 ◽  
pp. 875529302110275
Author(s):  
Carlos A Arteta ◽  
Cesar A Pajaro ◽  
Vicente Mercado ◽  
Julián Montejo ◽  
Mónica Arcila ◽  
...  
Keyword(s):  
South America ◽  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Motion Prediction ◽  
Depth Range ◽  
Ground Motion Prediction ◽  
Natural Period ◽  
Nazca Plate ◽  
Northern South America

Subduction ground motions in northern South America are about a factor of 2 smaller than the ground motions for similar events in other regions. Nevertheless, historical and recent large-interface and intermediate-depth slab earthquakes of moment magnitudes Mw = 7.8 (Ecuador, 2016) and 7.2 (Colombia, 2012) evidenced the vast potential damage that vulnerable populations close to earthquake epicenters could experience. This article proposes a new empirical ground-motion prediction model for subduction events in northern South America, a regionalization of the global AG2020 ground-motion prediction equations. An updated ground-motion database curated by the Colombian Geological Survey is employed. It comprises recordings from earthquakes associated with the subduction of the Nazca plate gathered by the National Strong Motion Network in Colombia and by the Institute of Geophysics at Escuela Politécnica Nacional in Ecuador. The regional terms of our model are estimated with 539 records from 60 subduction events in Colombia and Ecuador with epicenters in the range of −0.6° to 7.6°N and 75.5° to 79.6°W, with Mw≥4.5, hypocentral depth range of 4 ≤  Zhypo ≤ 210 km, for distances up to 350 km. The model includes forearc and backarc terms to account for larger attenuation at backarc sites for slab events and site categorization based on natural period. The proposed model corrects the median AG2020 global model to better account for the larger attenuation of local ground motions and includes a partially non-ergodic variance model.

scholarly journals Assessing Diazinon Pollution in the Three Major Rivers Flowing into the Caspian Sea (Iran)

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 335
Author(s):  
Reza Dahmardeh Behrooz ◽  
Abbas Esmaili-sari ◽  
Magdalena Urbaniak ◽  
Paromita Chakraborty
Keyword(s):  
High Risk ◽  
Organophosphorus Pesticides ◽  
Aquatic Organisms ◽  
The United States ◽  
The Caspian Sea ◽  
Worst Case ◽  
Pollution Levels ◽  
Haraz River ◽  
Significant Difference ◽  
Medium Risk

The aim of this study was to investigate the seasonal and spatial variations in the concentrations of a widely used organophosphorous pesticide (OPP), diazinon, and the associated risk posed by this OPP in the surface water from the three largest rivers located in the northern province of Iran: the Haraz, the Talar and the Babolrood rivers. These rivers are located in the agriculture province of Mazandaran, and are exposed to high doses of organophosphorus pesticides, especially diazinon. The concentration of diazinon was determined using gas chromatography, while the potential risk posed by diazinon was elucidated using a Risk Quotient (RQ) calculated for general (RQm) and worst-case (RQex) scenarios. The obtained results demonstrated that the average diazinon concentrations ranged from 41 ± 76 ng/L in the Talar River and 57 ± 116 ng/L in the Haraz River, to 76.5 ± 145 ng/L in the Babolrood River, with a significant difference noted between summer and autumn seasons for all three rivers. For some stations, the concentration of diazinon is higher than the standard guidelines of Australian/New Zealand Guidelines for Fresh and Marine Water Quality (FMWQ) and the United States Criteria Maximum Concentration (CMC). The calculated RQs indicated a medium risk of diazinon, RQm = 0.73 and RQex = 2.27, in the Talar River; RQm = 1.02 and RQex = 2.49 in the Haraz River; and RQm = 1.35 and RQex = 4.54 in the Babolrood River. The overall exposure of diazinon was defined to have a high risk (RQm and RQex > 1); however, the summer sampling revealed a high risk (RQm and RQex > 1), while the autumn had a medium risk (RQm and RQex < 1). The obtained results revealed not only elevated concentrations of diazinon in the studied rivers but most importantly the high risk posed by this OPP for the aquatic organisms and the wellbeing of the whole river ecosystem. The current study showed that development and implementation of appropriate standards and regulations toward diazinon in countries such as Iran are required to reduce the pollution levels and risks related to elevated concentrations of the studied pesticide.

scholarly journals Simulation of non-stationary stochastic ground motions based on recent Italian earthquakes

2021 ◽  
Author(s):  
Fabio Sabetta ◽  
Antonio Pugliese ◽  
Gabriele Fiorentino ◽  
Giovanni Lanzano ◽  
Lucia Luzi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Stochastic Simulations ◽  
Model Parameters ◽  
Motion Model ◽  
Arias Intensity ◽  
Time Frequency ◽  
Ground Motion Model ◽  
Ground Motion Records

AbstractThis work presents an up-to-date model for the simulation of non-stationary ground motions, including several novelties compared to the original study of Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996). The selection of the input motion in the framework of earthquake engineering has become progressively more important with the growing use of nonlinear dynamic analyses. Regardless of the increasing availability of large strong motion databases, ground motion records are not always available for a given earthquake scenario and site condition, requiring the adoption of simulated time series. Among the different techniques for the generation of ground motion records, we focused on the methods based on stochastic simulations, considering the time- frequency decomposition of the seismic ground motion. We updated the non-stationary stochastic model initially developed in Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996) and later modified by Pousse et al. (Bull Seism Soc Am 96:2103–2117, 2006) and Laurendeau et al. (Nonstationary stochastic simulation of strong ground-motion time histories: application to the Japanese database. 15 WCEE Lisbon, 2012). The model is based on the S-transform that implicitly considers both the amplitude and frequency modulation. The four model parameters required for the simulation are: Arias intensity, significant duration, central frequency, and frequency bandwidth. They were obtained from an empirical ground motion model calibrated using the accelerometric records included in the updated Italian strong-motion database ITACA. The simulated accelerograms show a good match with the ground motion model prediction of several amplitude and frequency measures, such as Arias intensity, peak acceleration, peak velocity, Fourier spectra, and response spectra.

scholarly journals Trissolcus japonicus (Hymenoptera: Scelionidae) Causes Low Levels of Parasitism in Three North American Pentatomids Under Field Conditions

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Joshua M Milnes ◽  
Elizabeth H Beers
Keyword(s):  
North American ◽  
Native Species ◽  
Classical Biological Control ◽  
The United States ◽  
Host Finding ◽  
Pest Species ◽  
Case Scenario ◽  
Worst Case ◽  
Egg Masses ◽  
Trissolcus Japonicus

Abstract Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys, but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the ‘worst case’ scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4–8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicus of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal.

The MacArthur Maze Fire and Roadway Collapse: A “Worst Case Scenario” for Spent Nuclear Fuel Transportation?

2012 ◽  
Author(s):  
Christopher S. Bajwa ◽  
Earl P. Easton ◽  
Harold Adkins ◽  
Judith Cuta ◽  
Nicholas Klymyshyn ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Steel Structure ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Severe Accident ◽  
Case Scenario ◽  
Worst Case ◽  
Work Related ◽  
Regulatory Commission

In 2007, a severe transportation accident occurred near Oakland, California, at the interchange known as the “MacArthur Maze.” The accident involved a double tanker truck of gasoline overturning and bursting into flames. The subsequent fire reduced the strength of the supporting steel structure of an overhead interstate roadway causing the collapse of portions of that overpass onto the lower roadway in less than 20 minutes. The US Nuclear Regulatory Commission has analyzed what might have happened had a spent nuclear fuel transportation package been involved in this accident, to determine if there are any potential regulatory implications of this accident to the safe transport of spent nuclear fuel in the United States. This paper provides a summary of this effort, presents preliminary results and conclusions, and discusses future work related to the NRC’s analysis of the consequences of this type of severe accident.

TREMOR: A Wireless MEMS Accelerograph for Dense Arrays

2005 ◽  
Vol 21 (1) ◽  
pp. 91-124 ◽  
Author(s):  
John R. Evans ◽  
Robert H. Hamstra ◽  
Christoph Kündig ◽  
Patrick Camina ◽  
John A. Rogers
Keyword(s):  
Spatial Resolution ◽  
Dynamic Range ◽  
Strong Motion ◽  
The United States ◽  
Companion Paper ◽  
Low Noise ◽  
Practical Reasons ◽  
Wireless Internet ◽  
Urban Centers ◽  
Strong Motion Network

The ability of a strong-motion network to resolve wavefields can be described on three axes: frequency, amplitude, and space. While the need for spatial resolution is apparent, for practical reasons that axis is often neglected. TREMOR is a MEMS-based accelerograph using wireless Internet to minimize lifecycle cost. TREMOR instruments can economically augment traditional ones, residing between them to improve spatial resolution. The TREMOR instrument described here has dynamic range of 96 dB between ±2 g, or 102 dB between ±4 g. It is linear to <1% of full scale (FS), with a response function effectively shaped electronically. We developed an economical, very low noise, accurate (<1%FS) temperature compensation method. Displacement is easily recovered to 10-cm accuracy at full bandwidth, and better with care. We deployed prototype instruments in Oakland, California, beginning in 1998, with 13 now at mean spacing of ∼3 km—one of the most densely instrumented urban centers in the United States. This array is among the quickest in returning (PGA, PGV, Sa) vectors to ShakeMap, ∼75 to 100 s. Some 13 events have been recorded. A ShakeMap and an example of spatial variability are shown. Extensive tests of the prototypes for a commercial instrument are described here and in a companion paper.

scholarly journals Interregional Transfers for Pandemic Surges

2020 ◽  
Author(s):  
Kenneth A Michelson ◽  
Chris A Rees ◽  
Jayshree Sarathy ◽  
Paige VonAchen ◽  
Michael Wornow ◽  
...  
Keyword(s):  
The United States ◽  
Upper Bounds ◽  
Hospital Inpatient ◽  
Worst Case ◽  
Icu Patients ◽  
Interregional Transfers ◽  
Number Of Patients ◽  
Bed Capacity ◽  
Model Scenarios ◽  
Do So

Abstract Background Hospital inpatient and intensive care unit (ICU) bed shortfalls may arise due to regional surges in volume. We sought to determine how interregional transfers could alleviate bed shortfalls during a pandemic. Methods We used estimates of past and projected inpatient and ICU cases of coronavirus disease 2019 (COVID-19) from 4 February 2020 to 1 October 2020. For regions with bed shortfalls (where the number of patients exceeded bed capacity), transfers to the nearest region with unused beds were simulated using an algorithm that minimized total interregional transfer distances across the United States. Model scenarios used a range of predicted COVID-19 volumes (lower, mean, and upper bounds) and non–COVID-19 volumes (20%, 50%, or 80% of baseline hospital volumes). Scenarios were created for each day of data, and worst-case scenarios were created treating all regions’ peak volumes as simultaneous. Mean per-patient transfer distances were calculated by scenario. Results For the worst-case scenarios, national bed shortfalls ranged from 669 to 58 562 inpatient beds and 3208 to 31 190 ICU beds, depending on model volume parameters. Mean transfer distances to alleviate daily bed shortfalls ranged from 23 to 352 miles for inpatient and 28 to 423 miles for ICU patients, depending on volume. Under all worst-case scenarios except the highest-volume ICU scenario, interregional transfers could fully resolve bed shortfalls. To do so, mean transfer distances would be 24 to 405 miles for inpatients and 73 to 476 miles for ICU patients. Conclusions Interregional transfers could mitigate regional bed shortfalls during pandemic hospital surges.

A Suite of Alternative Ground-Motion Models (GMMs) for Israel

2021 ◽  
Author(s):  
Soumya Kanti Maiti ◽  
Gony Yagoda-Biran ◽  
Ronnie Kamai
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Empirical Data ◽  
Epistemic Uncertainty ◽  
Ground Motions ◽  
Plate Boundary ◽  
Strong Motion ◽  
Engineering Applications ◽  
Motion Models ◽  
Ground Motion Models

ABSTRACT Models for estimating earthquake ground motions are a key component in seismic hazard analysis. In data-rich regions, these models are mostly empirical, relying on the ever-increasing ground-motion databases. However, in areas in which strong-motion data are scarce, other approaches for ground-motion estimates are sought, including, but not limited to, the use of simulations to replace empirical data. In Israel, despite a clear seismic hazard posed by the active plate boundary on its eastern border, the instrumental record is sparse and poor, leading to the use of global models for hazard estimation in the building code and all other engineering applications. In this study, we develop a suite of alternative ground-motion models for Israel, based on an empirical database from Israel as well as on four data-calibrated synthetic databases. Two host models are used to constrain model behavior, such that the epistemic uncertainty is captured and characterized. Despite the lack of empirical data at large magnitudes and short distances, constraints based on the host models or on the physical grounds provided by simulations ensure these models are appropriate for engineering applications. The models presented herein are cast in terms of the Fourier amplitude spectra, which is a linear, physical representation of ground motions. The models are suitable for shallow crustal earthquakes; they include an estimate of the median and the aleatory variability, and are applicable in the magnitude range of 3–8 and distance range of 1–300 km.

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