scholarly journals Scenario ensemble modelling of possible future earthquake impacts in Bhutan

2020 ◽  
Vol 103 (3) ◽  
pp. 3457-3478
Author(s):  
Tom R. Robinson
Keyword(s):  
Ensemble Modelling ◽  
Future Earthquake

After the Earth Quakes

2005 ◽  
Author(s):  
Susan Elizabeth Hough ◽  
Roger G. Bilham
Keyword(s):  
Natural Disasters ◽  
Earthquake Risk ◽  
Water Supplies ◽  
Major Earthquake ◽  
The Earth ◽  
Elastic Rebound ◽  
Future Earthquake ◽  
Human Capacity ◽  
Historic Earthquakes ◽  
Earthquake Science

Earthquakes rank among the most terrifying natural disasters faced by mankind. Out of a clear blue sky-or worse, a jet black one-comes shaking strong enough to hurl furniture across the room, human bodies out of bed, and entire houses off of their foundations. When the dust settles, the immediate aftermath of an earthquake in an urbanized society can be profound. Phone and water supplies can be disrupted for days, fires erupt, and even a small number of overpass collapses can snarl traffic for months. However, when one examines the collective responses of developed societies to major earthquake disasters in recent historic times, a somewhat surprising theme emerges: not only determination, but resilience; not only resilience, but acceptance; not only acceptance, but astonishingly, humor. Elastic rebound is one of the most basic tenets of modern earthquake science, the term that scientists use to describe the build-up and release of energy along faults. It is also the best metaphor for societal responses to major earthquakes in recent historic times. After The Earth Quakes focuses on this theme, using a number of pivotal and intriguing historic earthquakes as illustration. The book concludes with a consideration of projected future losses on an increasingly urbanized planet, including the near-certainty that a future earthquake will someday claim over a million lives. This grim prediction impels us to take steps to mitigate earthquake risk, the innately human capacity for rebound notwithstanding.

scholarly journals Implications of the Regional Earthquake Likelihood Models test of earthquake forecasts in California

2012 ◽  
Vol 2 (2) ◽  
pp. 10 ◽  
Author(s):  
Michael Karl Sachs ◽  
Ya-Ting Lee ◽  
Donald Turcotte ◽  
James R. Holliday ◽  
John B. Rundle
Keyword(s):  
Conditional Probability ◽  
Mean Value ◽  
Test Area ◽  
Test Period ◽  
Future Earthquake ◽  
The Mean ◽  
The One ◽  
Earthquake Likelihood Models ◽  
Regional Earthquake

The Regional Earthquake Likelihood Models (RELM) test was the first competitive comparison of prospective earthquake forecasts. The test was carried out over 5 years from 1 January 2006 to 31 December 2010 over a region that included all of California. The test area was divided into 7682 0.1°x0.1° spatial cells. Each submitted forecast gave the predicted numbers of earthquakes <em>N<sub>emi</sub></em> larger than <em>M</em>=4.95 in 0.1 magnitude bins for each cell. In this paper we present a method that separates the forecast of the number of test earthquakes from the forecast of their locations. We first obtain the number <em>N<sub>em</sub></em> of forecast earthquakes in magnitude bin <em>m</em>. We then determine the conditional probability <em>λ<sub>emi</sub></em>=<em>N<sub>emi</sub>/</em><em>N<sub>em</sub></em> that an earthquake in magnitude bin <em>m</em> will occur in cell <em>i</em>. The summation of <em>λ<sub>emi</sub></em> over all 7682 cells is unity. A random (no skill) forecast gives equal values of <em>λ<sub>emi</sub></em> for all spatial cells and magnitude bins. The <em>skill</em> of a forecast, in terms of the location of the earthquakes, is measured by the success in assigning large values of <em>λ<sub>emi</sub></em> to the cells in which earthquakes occur and low values of <em>λ<sub>emi</sub></em> to the cells where earthquakes do not occur. Thirty-one test earthquakes occurred in 27 different combinations of spatial cells <em>i</em> and magnitude bins <em>m</em>, we had the highest value of <em>λ<sub>emi</sub></em> for that <em>mi</em> cell. We evaluate the performance of eleven submitted forecasts in two ways. First, we determine the number of <em>mi</em> cells for which the forecast <em>λ<sub>emi</sub></em> was the largest, the best forecast is the one with the highest number. Second, we determine the mean value of <em>λ<sub>emi</sub></em> for the 27 <em>mi</em> cells for each forecast. The best forecast has the highest mean value of <em>λ<sub>emi</sub></em>. The success of a forecast during the test period is dependent on the allocation of the probabilities λemi between the mi cells, since the sum over the mi cells is unity. We illustrate the forecast distributions of <em>λ<sub>emi</sub></em> and discuss their differences. We conclude that the RELM test was successful in illustrating the choices required when a forecast of the location of a future earthquake is made.

scholarly journals Forensic investigation of Gumbasa irrigation main canal damage due to large-scale flow liquefaction in Sibalaya caused by the 2018 Sulawesi Earthquake

2021 ◽  
Vol 930 (1) ◽  
pp. 012079
Author(s):  
S Nurdin ◽  
A Arsyad ◽  
F A Marhum ◽  
H Setiawan
Keyword(s):  
Large Scale ◽  
Field Tests ◽  
Standard Penetration Test ◽  
Forensic Investigation ◽  
Flexible Pipe ◽  
Ground Movements ◽  
Before And After ◽  
Future Earthquake ◽  
Main Canal ◽  
Flow Liquefaction

Abstract This study conducted an extensive soil investigation in the Sibalaya liquefaction area to identify the Gumbasa main canal’s damage triggered by flow liquefaction. Several field tests and trenches with approximately 4 m were excavated to observe liquefied soil layers directly near the canal. A borehole, standard penetration test, and multichannel analysis surface waves (MASW) were performed beside the trench to obtain each layer’s penetration resistance. This research aims to understand the landslide’s whole aspect. The ground movements were analyzed by using satellite photos before and after the earthquake. The displacement of the main canal, the typical damage inventory, and the proposed reconstruction of the main canal are the focus of this study. As a result of the forensic investigation, the liquefied layers and debris flow contributing to the massive landslide were identified to impact the primary canal. The typical damage of the canal was due to surface rupture that occurred both horizontally and vertically. A solution for reconstructing the main canal is to use a flexible pipe canal structure. That will be resilient to future earthquake and ground movements, stabilize the ground downslope of the existing canal to limit the risk of future lateral movement in future earth tremors.

scholarly journals FireDST: a simulation system for short-term ensemble modelling of bushfire spread and exposure

2014 ◽  
pp. 1147-1158
Author(s):  
Ian A. French ◽  
Thomas J. Duff ◽  
Robert (Bob) P. Cechet ◽  
Kevin G. Tolhurst ◽  
Jeff D. Kepert ◽  
...  
Keyword(s):  
Simulation System ◽  
Short Term ◽  
Ensemble Modelling

scholarly journals Value of Injuries in the Northridge Earthquake

2006 ◽  
Vol 22 (2) ◽  
pp. 555-563 ◽  
Author(s):  
Keith Porter ◽  
Kim Shoaf ◽  
Hope Seligson
Keyword(s):  
Risk Mitigation ◽  
Economic Value ◽  
Northridge Earthquake ◽  
Confidence Bounds ◽  
Earthquake Research ◽  
Future Earthquake ◽  
The Cost ◽  
Nonfatal Injuries ◽  
The U.S ◽  
1994 Northridge Earthquake

The economic equivalent value of deaths and injuries in the 1994 Northridge earthquake has not previously been calculated, although number of injuries by category of treatment has. Using dollar-equivalent values for injuries accepted and used by the U.S. government for evaluating the cost-effectiveness of risk-mitigation efforts, the value of injuries in the 1994 Northridge earthquake is estimated to be $1.3 to 2.2 billion in 1994 (90% confidence bounds, equivalent to $1.8 to 2.9 billion in 2005). This is equivalent to 3–4% of the estimated $50 billion (in 1994) estimated direct capital losses and direct business interruption losses. If injuries in the 1994 Northridge earthquake are representative of injuries in future U.S. events, then the economic value of future earthquake injuries—the amount that the U.S. government would deem appropriate to expend to prevent all such injuries—is on the order of $200 million per year (in 2005 constant dollars). Of this figure, 96% is associated with nonfatal injuries, an issue overlooked by current experimental research. Given the apparently high cost of this type of loss, this appears to represent an important gap in the present earthquake research agenda.

scholarly journals Remote sensing inversion of lake water quality parameters based on ensemble modelling

2020 ◽  
Vol 143 ◽  
pp. 02007
Author(s):  
Li Xiaojuan ◽  
Huang Mutao ◽  
Li Jianbao
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Entropy Weight ◽  
Ensemble Modelling ◽  
Chl A ◽  
Inversion Model ◽  
Entropy Weight Method ◽  
Weight Method

In this paper, combined with water quality sampling data and Landsat8 satellite remote sensing image data, the inversion model of Chl-a and TN water quality parameter concentration was constructed based on machine learning algorithm. After the verification and evaluation of the inversion results of the test samples, Chl-a TN inversion model with high correlation between model test results and measured data was selected to participate in remote sensing inversion ensemble modelling of water quality parameters. Then, the ensemble remote sensing inversion model of water quality parameters was established based on entropy weight method and error analysis. By applying the idea of ensemble modelling to remote sensing inversion of water quality parameters, the advantages of different models can be integrated and the precision of water quality parameters inversion can be improved. Through the evaluation and comparative analysis of the model results, the entropy weight method can improve the inversion accuracy to some extent, but the improvement space is limited. In the verification of the two methods of ensemble modelling based on error analysis, compared with the optimal results of a single model, the determination coefficient (R2) of Chlorophyll a and TN concentration inversion results was increased from 0.9288 to 0.9313 and from 0.8339 to 0.8838, and the root mean square error was decreased from 14.2615 μ/L to 10.4194 μ/L and from1.1002mg/L to 0.8621mg/L. At the same time, with the increase of the number of models involved in the set modelling, the inversion accuracy is higher.

Interannual stability from ensemble modelling

2018 ◽  
Vol 75 (12) ◽  
pp. 2109-2113 ◽  
Author(s):  
Ian J. Stewart ◽  
Allan C. Hicks
Keyword(s):  
Stock Assessment ◽  
Base Case ◽  
Single Model ◽  
Sensitivity Testing ◽  
Ensemble Modelling ◽  
Temporal Correlations ◽  
Pacific Halibut ◽  
Simple Simulation ◽  
The Pacific ◽  
Hippoglossus Stenolepis

Ensemble modelling for fisheries analyses is increasing and may improve on single-model approaches through better representation of uncertainty, reduced potential for bias, and greater stability in results. Stability, defined here as deviations from model estimates as each year of data are added, may be due to the use of multiple models (rather than periodic changes to a single base-case model) and from the buffering effect of characterizing the central tendency with a set of models. However, stability against the addition of new data, although logically appealing, has not been explored for fisheries stock assessment. We use the Pacific halibut (Hippoglossus stenolepis) ensemble as an example and provide a simple simulation to explore the general behavior of results from an ensemble of models. Counterintuitively, we found the models in the halibut example showed high temporal correlations among deviations. However, we found that a small number of models with low among-model deviation correlations could show a stability benefit. Among-model deviation correlations may be a useful diagnostic for analysts developing ensembles or for those performing sensitivity testing of single-model assessments.

scholarly journals Discussions on disaster risk reduction for Padang City against tsunami by the seawall

2018 ◽  
Vol 229 ◽  
pp. 01009
Author(s):  
Paulus P. Rahardjo ◽  
Caroline Sutandi ◽  
Karyadi Kusliansjah ◽  
Pele Widjaja ◽  
Aflizal Arafianto ◽  
...  
Keyword(s):  
Disaster Risk Reduction ◽  
Disaster Risk ◽  
Literature Study ◽  
Future Earthquake ◽  
Preliminary Study ◽  
The Government ◽  
The City ◽  
Similar Risk ◽  
Banda Aceh

The 30 September 2009 Padang Pariaman (or West Sumatera Earthquake) (M = 7.6 USGS) has caused severe damages of buildings and infrastructures and fatalities. Many of the buildings failed may be due to the low quality of the structures or due to that most buildings were designed Indonesian code SNI 1726-2002, and many of them failed because of the occurrence of liquefaction causing foundation failures. However, a future earthquake could have been even more severe and causes a tsunami, a reality which we shall consider, especially because Padang City is located facing directly to the ocean. Based on the occurrence and experience in Banda Aceh, Padang City has similar risk and yet very limited barrier and lack of evacuation system. For evaluation of this issue, a team of Universitas Katolik Parahyangan conducted a preliminary study on the condition of Padang City and discuss some alternatives to be considered by the government or authority. Methods of research are based on a literature study and collected data for analysis. Options are discussed and conclusions are derived. This paper discusses the important lessons from Banda Aceh failures related to the tsunami, and method to reduce the disaster risk for Padang City by Tsunami Seawall. The purpose of this study is to discuss the risk of the tsunami at Padang City, the preparedness and local condition, and alternative actions to be carried out. There has been pro and cons for Seawall, but the study concluded that due to the fact that tsunami would reach the city within 15-30 minutes after the earthquake and condition of low lying elevation of the Padang City, the use of Seawall for city safety is worth to be considered.

Sign in / Sign up

Export Citation Format

Share Document