GRACE衛(wèi)星觀測到的尼泊爾8.1級地震前后的重力變化
發(fā)布時間:2018-04-10 04:16
本文選題:GRACE 切入點:尼泊爾地震 出處:《大地測量與地球動力學》2017年12期
【摘要】:利用GRACE衛(wèi)星重力資料,計算尼泊爾地震震中及周緣重力和地表密度時空變化,并獲取震源域特征點重力變化時間序列。結(jié)果表明,青藏高原內(nèi)部、印度北部及華南塊體東側(cè)重力以增加為主,喜馬拉雅與緬甸弧形帶重力呈逐年減少趨勢;尼泊爾地震發(fā)生在正負重力變化梯度帶上,且重力變化在2015年具有明顯的時間分段性特征,1~3月及地震發(fā)生的4月重力均以減小為主,5~9月以增加為主,12月以后以減小為主逐漸恢復;特征點時序揭示震源域重力呈長期減少趨勢,并在2013~2016年呈現(xiàn)出"增加-減少-增加-發(fā)震-減小"的變化特征;地表密度變化較好地反映出地表質(zhì)量遷移與重力變化的關系,為進一步理解尼泊爾地震的大陸動力學機制提供參考。
[Abstract]:Based on the GRACE satellite gravity data, the temporal and spatial variations of gravity and surface density in and around the Nepal earthquake are calculated, and the time series of gravity variation at characteristic points in the source region are obtained.The results show that the gravity of northern India and southern China blocks increases mainly in the Qinghai-Tibet Plateau, the gravity of the Himalayan and Myanmar arc belts decreases year by year, and the Nepal earthquake occurs in the gradient zone of positive and negative gravity variation.The gravimetric variation in 2015 has obvious time segmental characteristics: gravity decreases mainly from May to September and gradually recovers from December after the earthquake occurred in April and decreases mainly from May to September.The time series of feature points reveal a long-term decreasing trend of gravity in the focal region, and the variation characteristics of "increase-decrease-increase-increase-seismogenic-decrease" in 2013 ~ 2016, and the change of surface density reflects the relationship between surface mass migration and gravity change.It provides a reference for further understanding the continental dynamic mechanism of the Nepal earthquake.
【作者單位】: 長安大學地質(zhì)工程與測繪學院;中國地震局第二監(jiān)測中心;
【基金】:國家自然科學基金(41674001,41504005,41202189) 陜西省自然科學基礎研究計劃(2016JM4005) 中國博士后科學基金(2013M530412,2016M602741) 中國地震局地震行業(yè)科研專項(201208009) 中央高;究蒲袠I(yè)務費專項基金(310826172202)~~
【分類號】:P315.7
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本文編號:1729622
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