ESR dating has been widely used in seismic assessment. In this paper, we collected fault gouge samples systematically for ESR (Electron Spin Resonance) dating, and sediment samples of overlying strata, and offset stra...ESR dating has been widely used in seismic assessment. In this paper, we collected fault gouge samples systematically for ESR (Electron Spin Resonance) dating, and sediment samples of overlying strata, and offset strata for OSL (Optically Stimulated Luminescence) dating along Xiaoshan-Qiuchuan fault (XQF) trending NE-SW, Xiaofeng-Sanmen fault (XSF) trending NW-SE, and Changhua-Putuo fault (CPF) trending E-W. In the same fault outcrop, the ESR data of fault gouge is greater than the OSL data of the strata offset by fault. Therefore, the ESR data of fault gouge colleted in Hangzhou region do not represent the time of weak fault movement in Late Quaternary region, but represent the strong fault movements in Late Cenozoic. The episode of fault movement in Late Cenozoic could be speculated according to the ESR data: 1.000.58 Ma, there were strong fault movements along the XSF, XQF and CPF in Hangzhou region; 0.580.45 Ma, the fault movements of all faults became weaker and did not zero ESR signals significantly for ESR dating of fault movements; 0.450.20 Ma, there were strong fault movements along part of XQF; 0.10.01 Ma, there were fault movements along the XSF only, but the fault movements were not strong enough to reset the ESR signal; Since 0.01 Ma, the Hangzhou region tends to be stable. In addition, the XSF might be the division line of fault segmentation of XQF; there were strong fault movements along the southwest segment of XQF during 0.45 Ma to 0.20 Ma; while the fault movements along the northeast segment of XQF mainly occurred during 1.000.58 Ma.展开更多
本文采用ECMWF(European Centre for Medium-Range Weather Forecasts)细网格和NCEP(National Centers for Environmental Prediction)模式数据、NCEP 1°×1°再分析资料、降雪加密观测和常规资料,对2022年初的5次降雪过...本文采用ECMWF(European Centre for Medium-Range Weather Forecasts)细网格和NCEP(National Centers for Environmental Prediction)模式数据、NCEP 1°×1°再分析资料、降雪加密观测和常规资料,对2022年初的5次降雪过程进行对比分析,发现5次降雪过程均为雨转雪过程,且持续时间相对较短,平原为雨夹雪或小雪到中雪,山区中到大雪,局部暴雪,数值模式预报的积雪深度与实况相差甚远;大尺度环流形势为500 hPa中低纬南支槽或弱波动配合700 hPa上的暖湿气流和中低层冷空气,造成边界层浅薄的冷垫上温度骤降而在短时间内形成降雪;相较于平原地区,高山区上空温度层结与最大上升运动中心的配置,有利于降雪粒子较长时间维持在有利于枝状雪花的形成区域,且高山区云底云水含量显著偏低、整层温度足够低,故高山区更利于暴雪的形成。展开更多
基金Project of the Tenth Five-year Plan of Hangzhou Goverment and Earthquake Administration of Hangzhou (HZZFCG-2005-A4)
文摘ESR dating has been widely used in seismic assessment. In this paper, we collected fault gouge samples systematically for ESR (Electron Spin Resonance) dating, and sediment samples of overlying strata, and offset strata for OSL (Optically Stimulated Luminescence) dating along Xiaoshan-Qiuchuan fault (XQF) trending NE-SW, Xiaofeng-Sanmen fault (XSF) trending NW-SE, and Changhua-Putuo fault (CPF) trending E-W. In the same fault outcrop, the ESR data of fault gouge is greater than the OSL data of the strata offset by fault. Therefore, the ESR data of fault gouge colleted in Hangzhou region do not represent the time of weak fault movement in Late Quaternary region, but represent the strong fault movements in Late Cenozoic. The episode of fault movement in Late Cenozoic could be speculated according to the ESR data: 1.000.58 Ma, there were strong fault movements along the XSF, XQF and CPF in Hangzhou region; 0.580.45 Ma, the fault movements of all faults became weaker and did not zero ESR signals significantly for ESR dating of fault movements; 0.450.20 Ma, there were strong fault movements along part of XQF; 0.10.01 Ma, there were fault movements along the XSF only, but the fault movements were not strong enough to reset the ESR signal; Since 0.01 Ma, the Hangzhou region tends to be stable. In addition, the XSF might be the division line of fault segmentation of XQF; there were strong fault movements along the southwest segment of XQF during 0.45 Ma to 0.20 Ma; while the fault movements along the northeast segment of XQF mainly occurred during 1.000.58 Ma.
文摘本文采用ECMWF(European Centre for Medium-Range Weather Forecasts)细网格和NCEP(National Centers for Environmental Prediction)模式数据、NCEP 1°×1°再分析资料、降雪加密观测和常规资料,对2022年初的5次降雪过程进行对比分析,发现5次降雪过程均为雨转雪过程,且持续时间相对较短,平原为雨夹雪或小雪到中雪,山区中到大雪,局部暴雪,数值模式预报的积雪深度与实况相差甚远;大尺度环流形势为500 hPa中低纬南支槽或弱波动配合700 hPa上的暖湿气流和中低层冷空气,造成边界层浅薄的冷垫上温度骤降而在短时间内形成降雪;相较于平原地区,高山区上空温度层结与最大上升运动中心的配置,有利于降雪粒子较长时间维持在有利于枝状雪花的形成区域,且高山区云底云水含量显著偏低、整层温度足够低,故高山区更利于暴雪的形成。
