Probabilities of earthquake occurrences in Mainland Southeast Asia     

Santi Pailoplee  Montri Choowong 《Arabian Journal of Geosciences》2013,6(12):4993-5006

The frequency–magnitude distributions of earthquakes are used in this study to estimate the earthquake hazard parameters for individual earthquake source zones within the Mainland Southeast Asia. For this purpose, 13 earthquake source zones are newly defined based on the most recent geological, tectonic, and seismicity data. A homogeneous and complete seismicity database covering the period from 1964 to 2010 is prepared for this region and then used for the estimation of the constants, a and b, of the frequency–magnitude distributions. These constants are then applied to evaluate the most probable largest magnitude, the mean return period, and the probability of earthquake of different magnitudes in different time spans. The results clearly show that zones A, B, and E have the high probability for the earthquake occurrence comparing with the other seismic zones. All seismic source zones have 100 % probability that the earthquake with magnitude ≤6.0 generates in the next 25 years. For the Sagaing Fault Zone (zones C), the next Mw 7.2–7.5 earthquake may generate in this zone within the next two decades and should be aware of the prospective Mw 8.0 earthquake. Meanwhile, in Sumatra-Andaman Interplate (zone A), an earthquake with a magnitude of Mw 9.0 can possibly occur in every 50 years. Since an earthquake of magnitude Mw 9.0 was recorded in this region in 2004, there is a possibility of another Mw 9.0 earthquake within the next 50 years.  相似文献   

Effects of soil-engineering properties on the failure mode of shallow landslides     

Jonathan Peter McKenna  Paul Michael Santi  Xavier Amblard  Jacquelyn Negri 《Landslides》2012,9(2):215-228

Some landslides mobilize into flows, while others slide and deposit material immediately down slope. An index based on initial dry density and fine-grained content of soil predicted failure mode of 96 landslide initiation sites in Oregon and Colorado with 79% accuracy. These material properties can be used to identify potential sources for debris flows and for slides. Field data suggest that loose soils can evolve from dense soils that dilate upon shearing. The method presented herein to predict failure mode is most applicable for shallow (depth <5?m), well-graded soils (coefficient of uniformity >8), with few to moderate fines (fine-grained content <18%), and with liquid limits <40.  相似文献   

Introduction to the special issue on debris flows initiated by runoff, erosion, and sediment entrainment in western North America   总被引：2，自引：1，他引：1  

Jeffrey A. Coe  Susan H. Cannon  Paul M. Santi 《Geomorphology》2008,96(3-4):247

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Probabilistic Reasoning Over Seismic Time Series: Volcano Monitoring by Hidden Markov Models at Mt. Etna     

Carmelo Cassisi  Michele Prestifilippo  Andrea Cannata  Placido Montalto  Domenico Patanè  Eugenio Privitera 《Pure and Applied Geophysics》2016,173(7):2365-2386

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A pulsational approach to the luminosity of horizontal branch stellar structures     

Renato De Santis  Santi Cassisi 《Monthly notices of the Royal Astronomical Society》1999,308(1):97-110

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A study of methods to estimate debris flow velocity   总被引：8，自引：2，他引：6  

Adam B. Prochaska  Paul M. Santi  Jerry D. Higgins  Susan H. Cannon 《Landslides》2008,5(4):431-444

Debris flow velocities are commonly back-calculated from superelevation events which require subjective estimates of radii of curvature of bends in the debris flow channel or predicted using flow equations that require the selection of appropriate rheological models and material property inputs. This research investigated difficulties associated with the use of these conventional velocity estimation methods. Radii of curvature estimates were found to vary with the extent of the channel investigated and with the scale of the media used, and back-calculated velocities varied among different investigated locations along a channel. Distinct populations of Bingham properties were found to exist between those measured by laboratory tests and those back-calculated from field data; thus, laboratory-obtained values would not be representative of field-scale debris flow behavior. To avoid these difficulties with conventional methods, a new preliminary velocity estimation method is presented that statistically relates flow velocity to the channel slope and the flow depth. This method presents ranges of reasonable velocity predictions based on 30 previously measured velocities.  相似文献   

Predicting locations of post-fire debris-flow erosion in the San Gabriel Mountains of southern California     

J. E. Gartner  P. M. Santi  S. H. Cannon 《Natural Hazards》2015,77(2):1305-1321

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X‐shooter GTO observations and chemical tagging of two main‐sequence stars in the globular cluster NGC 2808     

A. Bragaglia  E. Carretta  R.G. Gratton  S. Lucatello  A. Milone  G. Piotto  V. D'Orazi  S. Cassisi  C. Sneden  R.L. Bedin 《Astronomische Nachrichten》2011,332(3):258-259

We observed two main sequence stars in the globular cluster NGC 2808, using X‐shooter. We selected one of the targets on the blue main sequence (bMS) and one on the red main sequence (rMS) and measured abundances for several light elements that are expected to be different in stars of first and second generations in globular clusters. The differences between the bMS and the rMS stars amply exceed the errors and is in agreement with a difference in products of hydrogen burning at high temperature. More data are required to put the findings on more solid basis and to try to distinguish between the different models proposed to explain the formation of globular clusters (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Comparison of debris-flow volumes from burned and unburned areas     

Paul M. Santi  Luca Morandi 《Landslides》2013,10(6):757-769

The goals of this work are to show the range of debris-flow volumes and watershed characteristics for several locations, and the differences in flow volumes for events triggered soon after wildfire. A dataset of 929 events was divided into groups based on location and burn status. The three unburned locations show significant differences: debris flows from the Italian Alps are larger and generate more debris per unit basin area or unit channel length than flows in the Western USA or in the Pacific Northwest. However, some of the observed differences may be attributed to the skew of the Italian Alps dataset towards larger events, and the small size and limited range of the Pacific Northwest data. For burned watersheds in the Western U.S. events, there is a clear progression in decreasing volume in debris flows as basins recover from the wildfire: it takes approximately 1 year, or at a few locations, as much as 3 years, for debris production to return to pre-fire rates. The difference is most apparent when the data are normalized for basin area (the area yield, which is 2× larger for burned basins) or for channel length (the length yield, which is 1.6× larger for burned basins). When normalized simultaneously for basin area, channel length, and channel gradient, burned areas produce significantly more debris (2.7–5.4 times as much). Burned areas in the Western USA are more sensitive to wildfire and produce larger debris flows than burned areas in more humid climates such as the Pacific Northwest.  相似文献   

Detecting discontinuities in GNSS coordinate time series with STARS: case study,the Bologna and Medicina GPS sites   总被引：1，自引：0，他引：1  

S. Bruni  Susanna Zerbini  F. Raicich  M. Errico  E. Santi 《Journal of Geodesy》2014,88(12):1203-1214

Global navigation satellite systems (GNSS) data are a fundamental source of information for achieving a better understanding of geophysical and climate-related phenomena. However, discontinuities in the coordinate time series might be a severe limiting factor for the reliable estimate of long-term trends. A methodological approach has been adapted from Rodionov (Geophys Res Lett 31:L09204, 2004; Geophys Res Lett 31:L12707, 2006) and from Rodionov and Overland (J Marine Sci 62:328–332, 2005) to identify both the epoch of occurrence and the magnitude of jumps corrupting GNSS data sets without any a priori information on these quantities. The procedure is based on the Sequential t test Analysis of Regime Shifts (STARS) (Rodionov in Geophys Res Lett 31:L09204, 2004). The method has been tested against a synthetic data set characterized by typical features exhibited by real GNSS time series, such as linear trend, seasonal cycle, jumps, missing epochs and a combination of white and flicker noise. The results show that the offsets identified by the algorithm are split into 48 % of true-positive, 28 % of false-positive and 24 % of false-negative events. The procedure has then been applied to GPS coordinate time series of stations located in the southeastern Po Plain, in Italy. The series span more than 15 years and are affected by offsets of different nature. The methodology proves to be effective, as confirmed by the comparison between the corrected GPS time series and those obtained by other observation techniques.  相似文献