In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with a long-baseline lightning location network of very-low-frequency/low-frequency magnetic field sensors. The results show that almost all of these cloud-to-ground(CG) strokes are produced during the mature stage of the MCS, and are predominantly located in the trailing stratiform region, which is similar to analyses of sprite-productive MCSs in North America and Europe. Comparison between the location results for the sprite-producing CG strokes and those provided by the World Wide Lightning Location Network(WWLLN) indicates that the location accuracy of WWLLN for intense CG strokes in Shandong Province is typically within 10 km, which is consistent with the result based on analysis of 2838 sprite-producing CG strokes in the continental United States. Also, we analyze two cases where some minor lightning discharges in the parent flash of sprites can also be located, providing an approach to confine the thundercloud region tapped by the sprite-producing CG strokes. 相似文献
A large paleolandslide occurred opposite the Gangda village in the upper Jinsha River, SE Tibetan Plateau. Field geological investigations and remote sensing indicated that the Gangda paleolandslide once blocked the Jinsha River. Evidence of river blocking, including landslide dam relics, upstream lacustrine sediments, and downstream outburst sediments, has been well preserved. To understand the river-blocking event including landslide, dam breach, and associated outburst flooding, optically stimulated luminescence (OSL) dating and numerical simulations were performed in this study. OSL dating results showed that the paleolandslide dam was formed at 5.4?±?0.5 ka BP and breached at 3.4?±?0.3 ka BP, indicating that the dam lasted approximately 2000 years. The discrete element method was used to simulate the dynamics of the Gangda rock landslide based on the restored topography, while a fluid–solid coupling model was performed to simulate the landslide dam breaching and flooding. The fluid–solid coupling model can simultaneously reflect the process of landslide-dam collapse and the propagation of outburst flood. The simulated results indicate that the whole landslide process lasted about 60 s with a peak velocity of 38 m/s. It is significant that the simulated morphology of the residual landslide dam and downstream outburst sediments is consistent with the field observations. The combined numerical investigation in this paper provided new insights into the research of landscape evolution and helped to understand the chain disaster of landslide, dam breach, and flooding.