Shallow Rupture of the 2011 Tarlay Earthquake (Mw 6.8), Eastern Myanmar

Abstract

We use L-band Advanced Land Observation Satellite PALSAR data to infer the distribution of subsurface fault slip during the Tarlay earthquake (M w 6.8) in eastern Myanmar. We find the total length of surface rupture is approximately 30 km, with nearly 2 m maximum surface offset along the westernmost section of the Nam Ma fault (the Tarlay segment). Finite-fault inversions constrained by Interferometric Synthetic Aperture Radar (InSAR) and pixel-tracking data suggest that fault slip is concentrated within the upper 10 km of the crust. Maximum slip exceeds 4 m at a depth between 3 and 5 km. Comparison between field measurements and near-fault deformation obtained from the InSAR range-offset result suggests about 10%-80% of displacement occurred within a 1 km wide zone off the main surface fault trace. This off-fault deformation may explain the shallow slip deficit that we observed during this earthquake. We estimate a recurrence interval for Tarlay-like events to be 1600-6500 yrs at this section of the Nam Ma fault. A detailed paleoseismological study is essential to clarify the slip behavior and the earthquake recurrence interval of the Nam Ma fault.

A semi-automated algorithm to quantify scarp morphology (SPARTA): application to normal faults in southern Malawi

“…Parameters β u and β l could be omitted if the synthetic catalogue is used to mimic an environment where fault scarps offset flat surfaces (e.g. Borah Peak fault scarp, Idaho; Ward and Barrientos, 1986) and included for regions where fault scarps offset sloped surfaces (e.g. Mangola fault scarp, central Apennines; Tucker et al, 2011).…”

“…The nature of the subsequent analysis and interpretation will, however, depend on the age and type of fault considered as well as the local lithological and climatic conditions. Individual earthquakes can produce scarps of variable height and a mix of on-fault and off-fault deformation (Wang et al, 2014;Gold et al, 2015;Milliner et al, 2016;Nissen et al, 2016). In some circumstances, ruptures are halted by discontinuities or steps in a fault system, whereas other earthquakes produce complex rupture patterns which include multiple fault segments (e.g.…”

Seismic hazards in Thailand: a compilation and updated probabilistic analysis

“…However, according to the severity of the two last hazardous earthquakes during 2011-2014, i.e., the M w 6.8 Tarlay (Wang et al 2014) and M L 6.3 Mae Lao (Soralump et al 2014) earthquakes, the estimated ground shaking (PGA) or earthquake intensity (MMI) is still underestimated, even though the PSHA presented here used the most up-to-date maps of Thailand. For the M L 6.3 Mae Lao earthquakes located at the Chiang Rai province, northern Thailand (latitude 19.66°N, longitude 99.67°E), the PGA measured at 20 and 1500 km distance from the epicenter is 0.3 and 0.00004 g, respectively (Soralump et al 2014).…”

“…1b,2), and suitable attenuation models for Thailand have been constrained differently (Chintanapakdee et al 2008). In addition, based on the latest hazardous earthquakes of 6.8 M w (Wang et al 2014) and 6.3 M L (Soralump et al 2014) that occurred on March 24, 2011, and May 5, 2014, respectively, in the vicinity of Thailand, Myanmar, and Laos, the PSHA in Thailand can be more accurately assessed using the up-to-date data and constrained models now available. The results obtained should help in the understanding of the severity of earthquake hazards and allow the necessary action to be taken to sustain the development of new, as well as the ongoing, engineering works, including serving as a resource for the further development of effective earthquake mitigation plans for Thailand.…”

Coseismic and Postseismic Displacement of 2011 Mw 6.8 Tarlay Earthquake, Myanmar using InSAR Techniques and Inversion Analysis

“…The faults are members of a group of left-lateral faults in Shan fault system posing as network triangle faults between Sagaing fault in Myanmar and Red River fault in northern Vietnam. Many large earthquakes occurred in this fault system since late 20 th century [6,7] as shown in Fig. 1.…”