地震地磁观测与研究
地震地磁觀測與研究
지진지자관측여연구
SEISMOLOGICAL AND GEOMAGNETIC OBSERVATION AND RESEARCH
2014年
1期
165-170
,共6页
曹建平%祝意青%韩美涛%李少睿
曹建平%祝意青%韓美濤%李少睿
조건평%축의청%한미도%리소예
陕西重力网%区域重力场%重力基准%重力变化%监测能力
陝西重力網%區域重力場%重力基準%重力變化%鑑測能力
협서중력망%구역중력장%중력기준%중력변화%감측능력
Shaanxi Gravity Monitoring Network%local gravity field%gravity datum%gravity change%monitoring ability
陕西重力网监测范围由关中盆地扩大到覆盖了鄂尔多斯块体南缘、关中盆地、秦岭山地及陕南、关中主要活动断裂带,同时与豫西、晋南、宁夏区域重力网实现了联网,测网监测能力由原来只具备对网内5级地震的监测提升到具备对发生在网内6级地震的监测。基于3个绝对重力基准约束下的重力观测平差结果表明,测网单位权中误差为7.7×10-8 m·s-2,平均点值中误差7.9×10-8m·s-2,当以2.5倍中误差作为限差时,可以识别发生在监测区域内40×10-8m·s-2左右的重力相对变化,为研究鄂尔多斯块体南缘重力场变化提供依据。
陝西重力網鑑測範圍由關中盆地擴大到覆蓋瞭鄂爾多斯塊體南緣、關中盆地、秦嶺山地及陝南、關中主要活動斷裂帶,同時與豫西、晉南、寧夏區域重力網實現瞭聯網,測網鑑測能力由原來隻具備對網內5級地震的鑑測提升到具備對髮生在網內6級地震的鑑測。基于3箇絕對重力基準約束下的重力觀測平差結果錶明,測網單位權中誤差為7.7×10-8 m·s-2,平均點值中誤差7.9×10-8m·s-2,噹以2.5倍中誤差作為限差時,可以識彆髮生在鑑測區域內40×10-8m·s-2左右的重力相對變化,為研究鄂爾多斯塊體南緣重力場變化提供依據。
협서중력망감측범위유관중분지확대도복개료악이다사괴체남연、관중분지、진령산지급협남、관중주요활동단렬대,동시여예서、진남、저하구역중력망실현료련망,측망감측능력유원래지구비대망내5급지진적감측제승도구비대발생재망내6급지진적감측。기우3개절대중력기준약속하적중력관측평차결과표명,측망단위권중오차위7.7×10-8 m·s-2,평균점치중오차7.9×10-8m·s-2,당이2.5배중오차작위한차시,가이식별발생재감측구역내40×10-8m·s-2좌우적중력상대변화,위연구악이다사괴체남연중력장변화제공의거。
Originally,Shaanxi Gravity Monitoring Network only covered Guanzhong basin.We ex-tended it to southern margin of Ordos′s block,Guanzhong basin,Qinling mountainous area and the main active faults of southern Shaanxi and Guanzhong.Meanwhile,we carried out the monitoring work by combing the local gravity monitoring network of western Henan, southern Shanxi,and Ningxia.Therefore,the monitoring ability was improved from monito-ring magnitude 5 earthquakes occurred within the network area to monitoring magnitude 6 earthquakes occurred within the network area.We processed the observation data based on a constraint of 3 absolute gravity data.The results indicate that the mean square error of unit weight is 7. 7 ×10-8 m·s-2 ,and the average mean square error of observed points is 7. 9 × 10-8 m·s-2 .It can detect the relative gravity change of 40 ×10-8 m·s-2 within the network area,when the tolerance is set as 2. 5 times of mean square error.This monitoring ability provides a basis of studying gravity change in southern Ordos′s block.