Test of the Predictability of the PI Method for Recent Large Earthquakes in and near Tibetan Plateau

2017 ◽  
pp. 217-232
Author(s):  
Yongxian Zhang ◽  
Caiyun Xia ◽  
Cheng Song ◽  
Xiaotao Zhang ◽  
Yongjia Wu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Pi Method ◽  
Large Earthquakes

Test of the Predictability of the PI Method for Recent Large Earthquakes in and near Tibetan Plateau

2017 ◽  
Vol 174 (6) ◽  
pp. 2411-2426 ◽  
Author(s):  
Yongxian Zhang ◽  
Caiyun Xia ◽  
Cheng Song ◽  
Xiaotao Zhang ◽  
Yongjia Wu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Pi Method ◽  
Large Earthquakes

scholarly journals Earthquake forecasting and its verification

2005 ◽  
Vol 12 (6) ◽  
pp. 965-977 ◽  
Author(s):  
J. R. Holliday ◽  
K. Z. Nanjo ◽  
K. F. Tiampo ◽  
J. B. Rundle ◽  
D. L. Turcotte
Keyword(s):  
Temporal Variations ◽  
Earthquake Forecasting ◽  
Earthquake Risk ◽  
Decision Threshold ◽  
New Approach ◽  
Pi Method ◽  
Time Prediction ◽  
Short Time ◽  
Large Earthquakes ◽  
Proven Method

Abstract. No proven method is currently available for the reliable short time prediction of earthquakes (minutes to months). However, it is possible to make probabilistic hazard assessments for earthquake risk. In this paper we discuss a new approach to earthquake forecasting based on a pattern informatics (PI) method which quantifies temporal variations in seismicity. The output, which is based on an association of small earthquakes with future large earthquakes, is a map of areas in a seismogenic region ("hotspots'') where earthquakes are forecast to occur in a future 10-year time span. This approach has been successfully applied to California, to Japan, and on a worldwide basis. Because a sharp decision threshold is used, these forecasts are binary--an earthquake is forecast either to occur or to not occur. The standard approach to the evaluation of a binary forecast is the use of the relative (or receiver) operating characteristic (ROC) diagram, which is a more restrictive test and less subject to bias than maximum likelihood tests. To test our PI method, we made two types of retrospective forecasts for California. The first is the PI method and the second is a relative intensity (RI) forecast based on the hypothesis that future large earthquakes will occur where most smaller earthquakes have occurred in the recent past. While both retrospective forecasts are for the ten year period 1 January 2000 to 31 December 2009, we performed an interim analysis 5 years into the forecast. The PI method out performs the RI method under most circumstances.

Identification of the Seismogenic Fault of the 1654 M 8.0 Tianshui Earthquake, Northeastern Tibetan Plateau

2021 ◽  
Author(s):  
Peng Chen ◽  
Wei Shi ◽  
Jianmin Hu ◽  
Bing Yan ◽  
Haifeng Lu
Keyword(s):  
Tibetan Plateau ◽  
Large Earthquake ◽  
Recurrence Interval ◽  
Seismogenic Fault ◽  
The Past ◽  
Northeastern Tibetan Plateau ◽  
New Evidence ◽  
Historic Earthquakes ◽  
Large Earthquakes ◽  
Morphogenic Earthquake

Abstract The 1654 M 8.0 Tianshui earthquake occurred in the triangle area bounded by the West Qinling fault (WQLF) and Lixian–Luojiabao fault (LLF) in the northeastern Tibetan plateau. Previous studies reported that the LLF is the source for this earthquake based on the historical records and the Holocene fault activities. However, topographic analyses, outcrop observations, trench excavations associated with the WQLF, together with the radiocarbon dating results reveal that (1) the most recent surface-rupturing earthquake (E1) occurred in the past 470 yr, which can only correspond to the 1654 Tianshui earthquake if the historic earthquakes record is complete. This result means that the seismogenic fault, which is responsible for the 1654 Tianshui earthquake is the WQLF, rather than the LLF as previously reported; (2) the penultimate morphogenic earthquake (E2) took place in the period of 2693–760 yr Cal B.P.; (3) the third recent large earthquake (E3) occurred in the period of 10,229–6032 yr Cal B.P. with a higher probability in this range of 9005–8596 yr Cal B.P.; and (4) in consideration of the double time span of event E3 when compared with event E2 and E1, there is a possibility that another morphogenic earthquake took place in the period of 8596–6032 yr Cal B.P., and then the fourth surface-rupturing event (E4) occurred in the period of 9005–8596 yr Cal B.P. Therefore, at least three or four Holocene slipping events have occurred upon the WQLF in the past ∼9000  yr, suggesting an average recurrence interval of large earthquakes of 2250–3000 yr. The new evidence associated with the source of the 1654 M 8.0 Tianshui earthquake and the recurrence interval of large earthquakes on the WQLF will throw light on the reassessment of seismic potential in this area.

scholarly journals A statistical feature of anomalous seismic activity prior to large shallow earthquakes in Japan revealed by the pattern informatics method

2014 ◽  
Vol 14 (4) ◽  
pp. 849-859 ◽  
Author(s):  
M. Kawamura ◽  
Y.-H. Wu ◽  
T. Kudo ◽  
C.-c. Chen
Keyword(s):  
Seismic Activity ◽  
Characteristic Time ◽  
Statistical Test ◽  
Time Span ◽  
Japan Meteorological Agency ◽  
Pi Method ◽  
Pattern Informatics ◽  
Shallow Earthquakes ◽  
The Relationship ◽  
Large Earthquakes

Abstract. To reveal the preparatory processes of large inland earthquakes, we systematically applied the pattern informatics (PI) method to earthquake data of Japan. We focused on 12 large earthquakes with magnitudes greater than M = 6.4 (based on the magnitude scale of the Japan Meteorological Agency) that occurred at depths shallower than 30 km between 2000 and 2010. We examined the relationship between the spatiotemporal locations of these large shallow earthquakes and the locations of PI hotspots, which correspond to grid cells of anomalous seismic activity during a designated time span. Based on a statistical test conducted using Molchan's error diagram, we investigated whether precursory anomalous seismic activity occurred in association with these large earthquakes and, if so, studied the characteristic time spans of such activity. Our results indicate that Japanese inland earthquakes with M ≥ 6.4 are typically preceded by anomalous seismic activity in timescales of 8–10 years.

scholarly journals A statistical feature of anomalous seismic activities prior to large shallow earthquakes in Japan revealed by the Pattern Informatics method

2013 ◽  
Vol 1 (2) ◽  
pp. 721-745
Author(s):  
M. Kawamura ◽  
Y.-H. Wu ◽  
T. Kudo ◽  
C. C. Chen
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Statistical Test ◽  
Time Span ◽  
Japan Meteorological Agency ◽  
Pi Method ◽  
Pattern Informatics ◽  
Shallow Earthquakes ◽  
Large Earthquakes ◽  
Earthquake Data

Abstract. For revealing the preparatory processes of large inland earthquakes, we systematically applied the Pattern Informatics method (PI method) to the earthquake data of Japan. We focused on 12 large earthquakes with magnitudes larger than M = 6.4 (an official magnitude of the Japan Meteorological Agency) that occurred at depths shallower than 30 km between 2000 and 2010. We examined the relation between the spatiotemporal locations of such large shallow earthquakes and those of PI hotspots, which correspond to the grid cells of anomalous seismic activities in a designated time span. Based on a statistical test using Molchan's error diagram, we inquired into the existence of precursory anomalous seismic activities of the large earthquakes and, if any, their characteristic time span. The test indicated that the Japanese M ≧ 6.4 inland earthquakes tend to be preceded by anomalous seismic activities of 8-to-10-yr time scales.

Evidence for Holocene Activity on the Jiali Fault, an Active Block Boundary in the Southeastern Tibetan Plateau

2020 ◽  
Vol 91 (3) ◽  
pp. 1776-1780
Author(s):  
Hu Wang ◽  
Kaijin Li ◽  
Lichun Chen ◽  
Xingqiang Chen ◽  
An Li
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Southeastern Part ◽  
Block Boundary ◽  
The Holocene ◽  
Hazard Assessments ◽  
Holocene Activity ◽  
Large Earthquakes ◽  
Active Block

Abstract Most active block boundary faults within the Tibetan plateau have been thought of as Holocene active, and are able to produce large earthquakes. However, it is unknown whether the Jiali fault (JLF) has been seismically active in the Holocene, which currently hampers efforts to undertake meaningful seismic hazard assessments near the southeastern part of the Tibetan plateau. In this study, it is shown that the JLF has indeed ruptured during the Holocene, as evidenced from geological, paleoseismic, and radiocarbon dating investigations. Specifically, at least two surface-rupturing paleoseismic events were revealed with ages between 2160±30  yr B.P. and 2680±30  yr B.P., and prior to 2730±30  yr B.P., respectively. Combined with previous studies on the JLF, we suggest that the fault (1) can be considered an active block boundary fault and (2) accommodates crustal deformation related to the uplift of the Tibetan plateau since the late Cenozoic.

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