波速线性变化介质中地震波传播特征

根据变速介质中地震波传播所满足的变系数波动方程,推导出波速线性变化介质中一维波动方程的解析解,讨论了波速不均匀性对地震波传播的影响：地震波振幅衰减大小与介质速度梯度有关;频率转折点两侧地震波传播性质;频率与地震波波速关系。     

古冲沟冲积扇体地震反射资料研究

利用地震资料研究古冲沟冲积扇体的反射特征、内部结构、剖面特征和分布特征等问题,研究结果为识别和确认古冲沟冲积扇体油气藏提供依据     

海底地震仪广角地震试验

介绍了海底地震仪(OBS)的基本原理、结构和海上调查方法,针对解决东海冲绳海槽地壳结构及性质等目的,利用大容量气枪枪阵震源和海底地震仪在东海冲绳海槽首次开展人工地震深部地球物理探测试验。本次试验布设一条NNW—SSE向垂直构造走向的勘测线,共投放海底地震仪40台,回收成功36台。获得了有效的深部地震数据,可识别到Pg、PmP、Pn等多种震相。此次试验是我国在冲绳海槽深部探测中的成功示范,有效填补了该地区深部地震数据的空白,为解决冲绳海槽深部地质问题奠定了坚实的基础。     

一例异育银鲫(Carassius auratus gibelio)暴发性出血病病原分析

2016年6月,江苏某异育银鲫(Carassius auratus gibelio)养殖场暴发一种传染性急性出血病,造成养殖银鲫大量死亡。为分析此次疾病病因及流行规律,本研究从发病养殖场采集患出血病的异育银鲫,从细菌、病毒及寄生虫三个方面对病原进行了分析。采用病原菌分离、组织病理学观察、超薄切片电镜观察、病毒核酸分析、回感实验等对病原进行鉴定。结果显示从发病鲫鱼体内分离到病毒一株,未发现寄生虫及细菌感染。经测序及序列分析,该病毒为鲤疱疹病毒Ⅱ型(Cyprinid herpesvirus2,CyHV-2)病毒,组织病理学观察结果显示患病鱼的鳃和肾脏有明显病变,电镜下可观察到病鱼脾脏组织有带囊膜的球形病毒,囊膜直径约为170—200nm,病毒衣壳直径约为110—120nm,核心直径约为60nm,用组织匀浆感染鲫鱼囊胚细胞系(CGB)可稳定地观察到典型的细胞病变,用患病鱼组织匀浆液人工感染异育银鲫的死亡率高达100%,荧光定量PCR检测到该病毒可感染多器官,其中以脾脏中病毒含量最高,其次是脑,肝脏中最少。本研究可为CyHV-2的诊断防控及疫苗研制提供资料。     

天然气水合物的声学探测模拟实验

在人工岩心中进行天然气水合物的生成和分解实验,同时获取了体系的温度、压力、声学特性(Vp和Vs、幅度和频率)及含水量等参数。经研究发现,温压法、超声探测法和TDR探测法都能灵敏探测沉积物中天然气水合物的形成和分解过程。分析认为,本次实验中水合物形成速率过快,只能宏观研究水合物对沉积物声学特性的影响,建议采用长岩心进一步研究沉积物中水合物的声学特性。     

The influence of differential sedimentary loading and compaction on the development of a deltaic rollover

Three-dimensional seismic data and wireline logs from the western Niger Delta were analyzed to reveal the sedimentary and tectonic history of a major deltaic growth-fault depocenter comprising a kilometer-scale rollover anticline. The seismic units of the rollover show a non-uniform thickness distribution with their respective maximum near the main bounding growth-fault on the landward side of the system. This wedge-shaped sediment-storage architecture ultimately reflects the non-uniform creation of accommodation space in the study area that was controlled by 1) the differential compaction of the hanging-wall and footwall strata, 2) the lateral variation of fault-induced tectonic subsidence above the listric master fault, and possibly 3) local subsidence related to the subsurface movement of mobile shale reacting to loading and buoyancy. A sequential three-dimensional decompaction of the interpreted deltaic rollover units allowed to reconstruct and measure the compaction development of the rollover succession through time, documenting that sediment compaction contributed per depositional interval to between 25 and 35% of the generation of depositional space subsequently filled by deltaic sediments. The incremental decompaction of sedimentary units was further used to quantify the cumulative amount of accommodation space at and around the studied rollover that was created by fault movement, shale withdrawal, regional tectonic subsidence, isostasy and changes in sea level. If data on the regional subsidence and eustasy are available, the contribution of these basinwide controls to the generation of depositional space can be subtracted from the cumulative accommodation balance, which ultimately quantifies the amount of space for sediments to accumulate created by fault movement or shale withdrawal. This observation is important in that it implies that background knowledge on subsidence, stratigraphic age and sea-level changes allows to reconstruct and quantify fault movement in syn-tectonic deltaic growth successions, and this solely based on hanging-wall isopach trends independent of footwall information.     

An energy-controlling boundary condition for partial wave reflections in the mild slope equation

An energy-controlling technique to actively manage the reflective property of waves from solid boundary is presented. As linear waves propagate through an energy-controlling area, a reduction in wave heights occurs due to energy dissipation, which can be placed under direct control through the imaginary part of the wavenumber and phase velocity. Based on this relationship, the present study investigates a new method to control reflected waves with desired heights in the mild slope equation model. The method is validated through numerical tests for various reflection coefficients and the results confirm the promising use of energy-controlling boundary condition for partial wave reflections.     

南黄海盆地二叠系地震地层特征与识别

南黄海盆地钻遇二叠系的井仅有4口,对大面积无井区(如崂山隆起)的地层特征认识不统一。从二叠系岩性特征和海陆钻井地层对比为出发点,结合二叠系内部及其上下地层的地震波组和速度特征,认为南黄海盆地二叠系分上下2段。上段为大隆—龙潭组含煤碎屑岩地层,煤系地层较薄且分布不稳定,存在相变特征,使得该组地层在地震反射特征上的规律性变差,地震上表现为较连续、中—高频反射和低速特征;下段为栖霞组灰岩夹泥页岩地层,地震上表现为较连续、中—低频反射和高速特征。在无井区识别二叠系时,抓住二叠系地层界面极性为"2负+1正"的强反射特征。下二叠统—中、上石炭统地震波组特征相似,由4~5个同相轴组成,厚度稳定(时间约为200 ms),地震波极性表现为"上正下负"的地层界面反射特征,可作为全区追踪的标准层。     

大陆边缘沉积盆地流体逸散管道地震特征及其成因机制

流体逸散管道是深部流体向上运移所形成的通道,在大陆边缘沉积盆地中广泛发育。由地震资料显示,流体逸散管道主要由根部、过路区和末端3部分组成。由于形成机制、起源和流体成分的不同,其组成三要素有不同的表现形式,因此,流体逸散管道类型多样,具有不同的地震反射特征。水力压裂是文献中最常见的一种有关流体逸散管道形成机制的解释,但是,随着地震勘探的发展和研究的不断深入发现,水力压裂不足以解释所有类型的流体逸散管道,还存在其他的成因机制,包括流化侵蚀作用、局部空洞坍塌及同沉积模式等。从流体逸散管道组成三要素的角度描述了不同类型流体逸散管道的地震反射特征,并详细论述了其4种成因机制下的形成过程。