CT理论与应用研究
CT理論與應用研究
CT이론여응용연구
COMPUTERIZED TOMOGRAPHY THEORY AND APPLICATIONS
2000年
z1期
90
,共1页
三维速度层析%多震相走时反演%波形反演%低速层
三維速度層析%多震相走時反縯%波形反縯%低速層
삼유속도층석%다진상주시반연%파형반연%저속층
3D-Velocity tomography%Multi-phase inversion%Wave-form inversion%iow velocity layer
本项成果包括:提出天然地震走时反演层析成像技术,采用下列方法使得处理结果得以改善:1)利用Pg,Sg,Pm,Sm,Pn,Sn等震相增大约束条件;2)用已有精度较高的人工地震测深结果作速度约束;3)用波形反演来修改模型,把波源,介质吸收,散射等全部物理特征集中反映在记录中,把诸多物理量开发出来互为约束,以修改后的模型再作反演,使解的稳定性大大提高;4)采用最优化过程,选择遗传算法。可以进行震源定位,走时反演,波形反演;5)得到任意深度的速度分布及从地表到Moho面的速度剖面。主要应用结果:对于朝鲜半岛南部,划分为5(沿纬度)*6(沿经度)*8(沿深度)块,对于中部分288块.得到从地表到M面的8个水平切面;中部地区沿纬度13个二维剖面及其Moho面深度分布。上述方法也用于祁连山中东段地壳三维结构成像加上地震台网数字记录,反演。该区属塔里木-阿拉善地块走廊过渡带与北祁连褶皱带;从剖面可看出该地块上地壳低速层厚,下地壳有-低速层。北祁连褶皱带盆地与隆起构造之间的起伏差异,显示古浪断裂与金强河断裂之间的深部差异与界线。两地区的结果表明,这些剖面对认识大地构造、地质结构的稳定性,深部事件的性质是很有益的,对地球动力学研究也有重要意义。
本項成果包括:提齣天然地震走時反縯層析成像技術,採用下列方法使得處理結果得以改善:1)利用Pg,Sg,Pm,Sm,Pn,Sn等震相增大約束條件;2)用已有精度較高的人工地震測深結果作速度約束;3)用波形反縯來脩改模型,把波源,介質吸收,散射等全部物理特徵集中反映在記錄中,把諸多物理量開髮齣來互為約束,以脩改後的模型再作反縯,使解的穩定性大大提高;4)採用最優化過程,選擇遺傳算法。可以進行震源定位,走時反縯,波形反縯;5)得到任意深度的速度分佈及從地錶到Moho麵的速度剖麵。主要應用結果:對于朝鮮半島南部,劃分為5(沿緯度)*6(沿經度)*8(沿深度)塊,對于中部分288塊.得到從地錶到M麵的8箇水平切麵;中部地區沿緯度13箇二維剖麵及其Moho麵深度分佈。上述方法也用于祁連山中東段地殼三維結構成像加上地震檯網數字記錄,反縯。該區屬塔裏木-阿拉善地塊走廊過渡帶與北祁連褶皺帶;從剖麵可看齣該地塊上地殼低速層厚,下地殼有-低速層。北祁連褶皺帶盆地與隆起構造之間的起伏差異,顯示古浪斷裂與金彊河斷裂之間的深部差異與界線。兩地區的結果錶明,這些剖麵對認識大地構造、地質結構的穩定性,深部事件的性質是很有益的,對地毬動力學研究也有重要意義。
본항성과포괄:제출천연지진주시반연층석성상기술,채용하렬방법사득처리결과득이개선:1)이용Pg,Sg,Pm,Sm,Pn,Sn등진상증대약속조건;2)용이유정도교고적인공지진측심결과작속도약속;3)용파형반연래수개모형,파파원,개질흡수,산사등전부물리특정집중반영재기록중,파제다물리량개발출래호위약속,이수개후적모형재작반연,사해적은정성대대제고;4)채용최우화과정,선택유전산법。가이진행진원정위,주시반연,파형반연;5)득도임의심도적속도분포급종지표도Moho면적속도부면。주요응용결과:대우조선반도남부,화분위5(연위도)*6(연경도)*8(연심도)괴,대우중부분288괴.득도종지표도M면적8개수평절면;중부지구연위도13개이유부면급기Moho면심도분포。상술방법야용우기련산중동단지각삼유결구성상가상지진태망수자기록,반연。해구속탑리목-아랍선지괴주랑과도대여북기련습추대;종부면가간출해지괴상지각저속층후,하지각유-저속층。북기련습추대분지여륭기구조지간적기복차이,현시고랑단렬여금강하단렬지간적심부차이여계선。량지구적결과표명,저사부면대인식대지구조、지질결구적은정성,심부사건적성질시흔유익적,대지구동역학연구야유중요의의。
This results including: A new technique of simultaneous inversion for 3-D seismic velocity structure using Pg, Sg PmP, SmS, Pn and Sn arrival times of 32 events with 404 seismic rays are inverted for locations and crustal structure, these is applied to the Center of the Korean Peninsula and Qilianshan Mt 3-D seismic velocity tomography including 8-sections from earth surface to the Moho, 13profiles along latitude and longitude, and depth distribution was determined. The velocities fluctuate strongly in the upper crust; There are big anisotrophy bodies near north of Seoul in upper crust, implying that they may be related to deep fault system of Chugaryong Rift Valley. They found that there were low velocity bodies under the Kyongju area at the depth 10- 15 km under the Youngwol area at the depth l0 km, at the Hongsung area at the depth 5-10 km, indicating that they may be related to the earthquake source of Kyongju (6/25/1997), Youngwol (12/13/1996), and Hongsung (10/07/1978),respectively. These results are also consistent with Bouguer gravity anomalies showing very complex and low velocity bodies beneath the Chugaryong Rift Valley and/or deep fault systems and the earthquake hypocenters, respectively.