As revealed by field investigations, the co-seismic surface rupture zone of the 2010 M S 7.1 Yushu earthquake, Qinghai is a characteristic sinistral strike-slip feature consisting of three distinct sinistral primary ruptures, with an overall strike of 310°-320° and a total length of 31 km. In addition, an approximately 2-km-long en-echelon tensile fissure zone was found east of Longbao Town; if this site is taken as the north end of the rupture zone, then the rupture had a total length of ~51 km. The surface rupture zone is composed of a series of fissures arranged in an en-echelon or alternating relationship between compressive bulges and tensile fissures, with a measured maximum horizontal displacement of 1.8 m. The surface rupture zone extends along the mapped Garzê-Yushu Fault, which implicates it as the seismogenic fault for this earthquake. Historically, a few earthquakes with a magnitude of about 7 have occurred along the fault, and additionally traces of paleoearthquakes are evident that characterize the short-period recurrence interval of large earthquakes here. Similar to the seismogenic process of the 2008 Wenchuan earthquake, the Yushu earthquake is also due to the stress accumulation and release on the block boundaries resulting from the eastward expansion of Qinghai-Tibet Plateau. However, in contrast with the Wenchuan earthquake, the Yushu earthquake had a sinistral strike-slip mechanism resulting from the uneven eastward extrusion of the Baryan Har and Sichuan-Yunnan fault blocks. M S 7.1 Yushu earthquake, surface rupture, large historical earthquakes, Garzê-Yushu Fault Citation: Chen L C, Wang H, Ran Y K, et al. The M S 7.1 Yushu earthquake surface rupture and large historical earthquakes on the Garzê-Yushu Fault. At 7 : 49 on April 14, 2010, an M s 7.1 earthquake occurred in Yushu County, Yushu Tibetan Autonomous Prefecture, Qinghai Province, China. The earthquake left more than 2200 people dead and destroyed more than 80% of the buildings in Jiegu Town. It was one of the largest earthquakes experienced in the region since the 2008 M s 8.0 Wenchuan earthquake, causing huge losses of life and property in China. The seismotectonic setting and earthquake surface rupture characteristics for this earthquake and the recurrence pattern of major earthquakes on the seismogenic faults in this area are major concerns of community and a focus of research activity. *Corresponding author (email: ykran@263.net)The investigation and discussion of such issues as soon as possible after an earthquake occurs can provide important reference information for post-earthquake reconstruction and delineate key surveillance and protection regimes for future large earthquakes. Based on the first field survey to be conducted in the area after the earthquake, we aim to depict the co-seismic surface ruptures of the Yushu earthquake and to analyze the seismogenic structures and earthquake recurrence characteristics in combination with historical earthquake records and paleoseismology surveys.

Rapid socioeconomic development in earthquake-prone areas can cause rapid changes in seismic loss risks. These changes make it difficult to ensure that risk reduction strategies are realistic, practical and effective over time. To overcome this difficulty, ongoing changes in risk should be captured timely, definitively, and accurately and then specific and well-timed adjustments of the relevant strategies should be made. However, methods for rapidly characterizing such seismic disaster risks over a large area have not been sufficiently developed. By focusing on building loss risks, this paper presents the development of an integrated method that combines remote sensing data and local OPEN ACCESSRemote Sens. 2015, 7 2544 knowledge to resolve this problem. This method includes two key interdependent steps.(1) To extract the heights and footprint areas of a large number of buildings accurately and quickly from single high-resolution optical remote sensing images; (2) To estimate the floor areas, identify structural types, develop damage probability matrixes, and determine economic parameters for calculating monetary losses due to seismic damage to the buildings by reviewing building-relevant local knowledge based on these two parameters (i.e., the building heights and footprint areas). This method is demonstrated in the Tangshan area of China. Based on the integrated method, the total floor area of the residential and public office buildings in central Tangshan in 2009 was 3.99% lower than the corresponding area number obtained by a conventional earthquake loss estimation project. Our field-based verification indicated that the mean relative error of the method for estimating the floor areas of the assessed buildings was 2.99%. A simulation of the impacts of the 1976 Ms 7.8 Tangshan earthquake using this method indicated that the total damaged floor area of the residential and public office buildings and the associated direct monetary loses in the study area could have been 8.00 and 28.73 times greater, respectively, than in 1976 if this earthquake had recurred in 2009, which is a strong warning to the local people regarding the increasing challenges they may face.

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Based on data from a questionnaire survey about the 2010 Ms 7.1 Yushu earthquake in Qinghai Province, China, this study examines the impacts of belief in Tibetan Buddhism on Tibetans' response to the earthquake disaster. The results reveal that (1) impacted by their belief in Tibetan Buddhism, some Tibetans attribute the cause of the earthquake to punishment from God even though some of them understand a naturalistic explanation of the earthquake. Religious attribution of the earthquake has negative effects on Tibetans' awareness of the importance of earthquake disaster risk reduction such as learning about earthquakes and developing earthquake survival skills; their ability with regard to their behavioral response is affected, but their psychological reaction is not. (2) Tibetan Buddhist belief and Tibetan Buddhist clergy served as important resources and support to help Tibetans cope with the earthquake disaster. The degree of religiosity was found to be positively correlated with people's willingness to seek religious support and with their self-evaluations on the importance of religious support for disaster response. The findings of this study highlight the need to carefully consider local religious beliefs when planning disaster risk reduction strategies in Tibetan communities.

China is one of the most earthquake-prone countries in the world. The highest-priority mission after an earthquake is to rapidly save lives, and to minimize the loss of life. Rapid judgment of the trapped personnel location is the important basis to identify the emergency supply demands and carry out the search and rescue work after the earthquake. Through analyzing the main influencing factors, we constructed an assessment model of people trapped in collapsed buildings caused by the earthquakes. The accuracy of the estimation results from the model was then tested against the actual investigation data in 2014 Ludian earthquake-hit area. Results showed that, the trapped personnel distribution assessed by this model is generally concordant with that obtained by the actual survey in Ludian earthquake. The grid-based assessment of people trapped in earthquakes can meet the requirements of key search and rescue zone identification and rescue forces allocation in the early stage of earthquake emergency. Although there were some limitations in the study, it offers a simple and rapid approach for assessing the trapped people losses based on basic empirical data. The approach can be further improved to provide more information and suggestions for earthquake emergency search and rescue.