scholarly journals Temporal Variation and Statistical Assessment of the b Value off the Pacific Coast of Tokachi, Hokkaido, Japan

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 249 ◽  
Author(s):  
Weiyun Xie ◽  
Katsumi Hattori ◽  
Peng Han
Keyword(s):  
Temporal Variation ◽  
Pacific Coast ◽  
Statistical Significance ◽  
B Value ◽  
Statistical Assessment ◽  
Significance Level ◽  
B Values ◽  
The Pacific ◽  
Bootstrap Approach ◽  
Large Earthquakes

: The Gutenberg-Richter Law describes the frequency-magnitude distribution of earthquakes. A number of studies have shown that the slope (b value) of the relationship between frequency and magnitude decreased before large earthquakes. In this paper, we investigate the temporal variation of the b value off the Pacific coast of Tokachi, Hokkaido, Japan, during 1990–2014. The magnitude of completeness (Mc) in the catalog is evaluated by combining the maximum curvature (MAXC) technique and the bootstrap approach. Then, the b value, and its uncertainty, is computed by using the maximum likelihood estimation. The Akaike Information Criterion (AIC) with the bootstrap approach is introduced to statistically assess the temporal variation of b values and quantify the significance level. The results show a decrease in trends of the b value prior to two large earthquakes (26 September 2003 (M8.0) and 11 September 2008 (M7.1)) in the analyzed area. In addition, the decrease of b values shows certain statistical significance three months before the 2003 Earthquake off the Pacific coast of Tokachi (M8.0). It is concluded that the b value with statistical assessment may contain potential information for future large earthquake preparation off the Pacific coast of Tokachi, Hokkaido, Japan.

scholarly journals The Spatio-temporal Analysis of b-value in the Banda Arc, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana
Keyword(s):  
Temporal Variation ◽  
Temporal Analysis ◽  
B Value ◽  
Spatial And Temporal Variation ◽  
Tectonic Structure ◽  
Time Period ◽  
Banda Arc ◽  
Spatio Temporal ◽  
The Impact ◽  
Large Earthquakes

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.

scholarly journals Unusual Animal Behavior Preceding the 2011 Earthquake off the Pacific Coast of Tohoku, Japan: A Way to Predict the Approach of Large Earthquakes

Animals ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 131-145 ◽  
Author(s):  
Hiroyuki Yamauchi ◽  
Hidehiko Uchiyama ◽  
Nobuyo Ohtani ◽  
Mitsuaki Ohta
Keyword(s):  
Animal Behavior ◽  
Pacific Coast ◽  
The Pacific ◽  
Large Earthquakes

scholarly journals The Marine Radiocarbon Reservoir Effect in Tomales Bay, California

Radiocarbon ◽  
2018 ◽  
Vol 60 (3) ◽  
pp. 963-974 ◽  
Author(s):  
Lee M Panich ◽  
Tsim D Schneider ◽  
Paul Engel
Keyword(s):  
Temporal Variation ◽  
Late Holocene ◽  
Pacific Coast ◽  
Archaeological Sites ◽  
Northern Coast ◽  
Museum Collection ◽  
Reservoir Effect ◽  
The Pacific ◽  
R Value ◽  
Tomales Bay

ABSTRACTThis paper examines the marine reservoir effect for Tomales Bay, a 25.5-km-long tidal estuary along the northern coast of California. We determined the regional ∆R through radiocarbon (14C) measurements of pre-1950 shells from a museum collection as well as archaeologically recovered shell samples from a historical railroad grade of known construction date. These results are compared against four sets of paired shell and bone samples from two local archaeological sites. Our results indicate little spatial variation along the inner bay, but the proposed ∆R value is lower than those previously reported for nearby areas along the Pacific Coast. We also note potential variability in regional ∆R of approximately 200 14C years for the late Holocene, and comparison with an older paired bone and shell sample points toward more significant temporal variation earlier in time.

scholarly journals Assessing Earthquake Forecast Performance Based on b Value in Yunnan Province, China

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 730
Author(s):  
Rui Wang ◽  
Ying Chang ◽  
Miao Miao ◽  
Zhiyi Zeng ◽  
Hongyan Chen ◽  
...  
Keyword(s):  
Yunnan Province ◽  
B Value ◽  
Process Models ◽  
Earthquake Forecast ◽  
Forecast Performance ◽  
B Values ◽  
Systematic Assessment ◽  
Forecast Efficiency ◽  
Point Process Models ◽  
Large Earthquakes

Many studies have shown that b values tend to decrease prior to large earthquakes. To evaluate the forecast information in b value variations, we conduct a systematic assessment in Yunnan Province, China, where the seismicity is intense and moderate–large earthquakes occur frequently. The catalog in the past two decades is divided into four time periods (January 2000–December 2004, January 2005–December 2009, January 2010–December 2014, and January 2015–December 2019). The spatial b values are calculated for each 5-year span and then are used to forecast moderate-large earthquakes (M ≥ 5.0) in the subsequent period. As the fault systems in Yunnan Province are complex, to avoid possible biases in b value computation caused by different faulting regimes when using the grid search, the hierarchical space–time point-process models (HIST-PPM) proposed by Ogata are utilized to estimate spatial b values in this study. The forecast performance is tested by Molchan error diagram (MED) and the efficiency is quantified by probability gain (PG) and probability difference (PD). It is found that moderate–large earthquakes are more likely to occur in low b regions. The MED analysis shows that there is considerable precursory information in spatial b values and the forecast efficiency increases with magnitude in the Yunnan Province. These results suggest that the b value might be useful in middle- and long-term earthquake forecasts in the study area.

The Philological Association of The Pacific Coast

PMLA ◽  
1935 ◽  
Vol 50 (4) ◽  
pp. 1373-1374
Keyword(s):  
Annual Meeting ◽  
Pacific Coast ◽  
Stanford University ◽  
The Pacific

The thirty-seventh annual meeting of the Philological Association of the Pacific Coast was held at Stanford University, California, on November 29 and 30, 1935.

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