Characteristics of Tsunamis Propagating over Oceanic Ridges: Numerical Simulation of the 1996 Irian Jaya Earthquake Tsunami

The 1996 Irian Jaya earthquake tsunami was simulated by using the numerical model based on the linear long wave theory including Coriolis force in the spherical coordinate system. The numerical modeling result at Chichijima is in good agreement with the observed tide gauge data. The distinctive oscillation at Chichijima can be interpreted as the formation of boundary waves, so called ridge waves that are excited on the South-Honshu ridge. The mechanism of tsunami propagation trapped on an oceanic ridge is analyzed with the simple ridge model. The result explains the characteristics of ridge waves excited on theSouth-Honshu ridge.     

汶川震区映秀镇"8·14"特大泥石流灾害调查

2010年8月14日强降雨过程导致汶川震区映秀镇红椿沟泥石流暴发,泥石流堰塞堆积体堵断岷江主河道,导致河水改道冲入映秀新镇,引发洪水泛滥;造成映秀镇13人死亡、59人失踪,受灾群众8 000余人被迫避险转移.由于这场泥石流灾害发生在汶川地震震中区,是地震与降雨共同作用下的结果,研究其形成与成灾过程对于进一步认识强震区泥...     

Socotra Island,Yemen: field survey of the 2004 Indian Ocean tsunami

The tsunami of 26th December 2004 severely affected Yemen’s Socotra Island with a death at a distance of 4,600 km from the epicenter of the Magnitude 9.0 earthquake. Yemen allowed a detailed assessment of the far-field impact of a tsunami in the main propagation direction. The UNESCO mission surveyed 12 impacted towns on the north and south shores covering from the east to the west tip of Socotra. The international team members were on the ground in Yemen from 11 to 19 October 2006. The team measured tsunami run-up heights and inundation distances based on the location of watermarks on buildings and eyewitness accounts. Maximum run-up heights were typically on the order of 2–6 m. Each measurement was located by means of global positioning systems (GPS) and photographed. Numerous eyewitness interviews were recorded on video. The tsunami impact on Socotra is compared with other locations along the shores of the Indian Ocean.     

Importance of active tectonics during karst formation. A Middle Eocene to Pleistocene example of the Lina Moutains (Irian Jaya,Indonesia)

Abstract

The Lina Moutains show a typical example of karst formation associated to recent and active tectonics. The limestone samples were collected from giant potholes present beneath the heavy rainforest, during speleological expeditions to the Bird’s Head of Irian-Jaya. Micropalaeontological data allow us to give a Middle Pleistocene age for the most recent karst formation. A detailed stratigraphy between the Upper Lutetian and the Middle Pleistocene was recorded, with tectonic events during the Oligocene and Pleistocene. The edge of the resurgence layer was also dated. We also conclude the probable existence of a subterraneous network downhill of the karst within the most recent levels of the Kais Limestone formation. We replace this formation within the tectonic evolution of this area between the Eocene and the Middle Pleistocene, in conjunction with the oblique convergence of the Pacific plate carrying volcanic arc fragments and the Australian margin, which resulted in folding, normal faulting associated with local extension, and wrench motion, which are settings capable of creating uplift of the carbonated platform. © Elsevier, Paris     

Run-up and Inundation Pattern Developed During the Indian Ocean Tsunami of December 26, 2004 Along the Coast of Tamilnadu (India)

The tsunami run-up, inundation and damage pattern observed along the coast of Tamilnadu (India) during the deadliest Indian Ocean tsunami of December 26, 2004 is documented in this paper. The tsunami caused severe damage and claimed many victims in the coastal areas of eleven countries, bordering the Indian Ocean. Along the coast of Indian mainland, the damage was caused by the tsunami only. Largest tsunami run-up and inundation was observed along the coast of Nagapattinam district and was about 10–12 m and 3.0 km, respectively. The measured inundation data were strongly scattered in direct relationship to the morphology of the seashore and the tsunami run-up. Lowest tsunami run-up and inundation was measured along the coast of Thanjavur, Puddukkotai and Ramnathpuram districts of Tamilnadu in the Palk Strait. The presence of shadow of Sri Lanka, the interferences of direct/receded waves with the reflected waves from Sri Lanka and Maldive Islands and variation in the width of continental shelf were the main cause of large variation in tsunami run-up along the coast of Tamilnadu.     

Tsunami evacuation behavior of coastal residents in Kochi Prefecture during the 2014 Iyonada Earthquake

The 2014 Iyonada Earthquake, which occurred at 02:06 JST on 14 March, measured 6.2 on the Richter scale and originated in the Seto Inland Sea of Japan. To elucidate tsunami evacuation behavior, we examined two coastal communities in Kochi Prefecture, Okitsu and Mangyo, where residents evacuated to high ground in anticipation of a tsunami. In the event of a Nankai megathrust earthquake and tsunami, it is expected that a huge tsunami will be generated and these communities will be severely damaged. Before the Iyonada Earthquake, we had previously collected data about tsunami preparedness and evacuation plans from the residents of these communities, and after the earthquake, we conducted in-depth interviews and questionnaire surveys with the residents regarding the actual evacuation behaviors that they took. This enabled us to compare evacuation plans with evacuation behaviors. Results indicate that many residents responded quickly to the earthquake, either by immediately evacuating to emergency shelters on high ground or by preparing themselves for evacuation. Additionally, the earthquake revealed great differences between the prior evacuation plans and the actual situation of residents’ evacuation, such as specific triggers that significantly led residents to evacuate and the use of vehicles in evacuation.     

川西新场气田全三维压力预测方法研究

针对川西地区新场气田超高压气藏，利用三维采集的地震资料，在改善叠前CDP道集信噪比和速度谱质量的基础上，采用等时间隔层速度法，根据Fillippone的压力计算公式，直接预测地层压力，得到了全三维的压力和偏差压力数据体。压力预测结果表明，该方法具有较好的可信度。     

关于上海及邻区震源深度的探讨

利用上海及邻区的最新地震资料,对其全区和四个小区的震源深度与震级、震源深度与频次的关系进行初步探讨,并对三个典型震(群)区的震源深度加以分析,最后提出了对上海地区地震活动性和震源深度研究的几点认识。     

Damage Survey of Water Supply Systems and Fragility Curve of PVC Water Pipelines in the Chi–Chi Taiwan Earthquake

Substantial damage to water supply systems, including water delivery pipelines, water treatment plants, reservoirs, and water storage tanks, was reported after the 1999 Chi–Chi Taiwan Earthquake. This paper first summarizes the damage survey and then presents the results of seismic fragility analysis for underground pipelines. Construction blueprints of the water delivery pipelines and repair work orders of 11 townships and cities in the disastrous area were digitized into a Geographical Information System (GIS) for analysis and assessment. With the aid of the GIS system, we found that PVC pipes made up 86% of water delivery pipelines while steel, cast iron, ductile iron, PE and others took the rest. Therefore, this paper focuses on the fragility analysis of PVC pipes. Three different methods were applied to derive the fragility relations between the PVC water pipes having nominal diameters (approximately inner diameters) greater than or equal to 65 mm and earthquake intensity parameters such as peak ground acceleration and peak ground velocity. The results were then examined with those of other countries. The discrepancy between our results and the empirical equation used by HAZUS, an earthquake loss estimation software developed by the Federal Emergency Management Agency was not significant.     

试用地球系统科学观解读2004年印度洋地震海啸

2004年印度洋地震海啸是本世纪初全球发生的最为惨重的自然灾害.这次地震海啸涉及地球的岩石圈、水圈、大气圈和生物圈,甚至还有地外星球和月球的作用,造成能量与物质之间的相互转化与传递,说明地球是一个完整的统一整体.因此,对地震海啸等自然灾害必须采用地球系统科学观进行分析和研究,找出彼此之间的相互关系、形成机制和演化规律,并用信息化、全球化和可持续发展的地球科学观来研究和防御地震海啸.     

吉林省东部煤田地震资料解释精度低的原因分析

在地震资料解释过程中,吉林省东部聚煤盆地地震资料同相轴频率相对其他地区同一反射时的同相轴频率普遍偏低,通过提频处理也难与其他地区相比,其小断层解释符合率比较低。通过对比分析,正确地认识地震资料有利于小构造的划分和断定。     

Deep Structure and Distribution of Earthquake in the Manzhouli-Suifenhe Geotransect Region

1.IntroductionTheManzhouli-SuifenheGeoscienceTransect(M-SGT)isinthenortheastChina,acrosstheprovincesofInnerMongoliaandHeilongiiang.Geologically,itissitllatedamongtheplatesofNorthChina,SiberiaandWesternPacific.ThewholeIengthoftheM-SGTisaboutl3Ookm,whichcrossesmanytectonicunits(Fig.l).ItisclearthatitstectonicsitUationisuniqueanditsgeologicstructUreiscomplex.Deepearthquakeshappenfrequentlya1ongthetransect.Therefore,itisarepresentativeprofileofnortheastChinaandtheNortheastAsia.TheM-S…     

The 3 June 1994 Java Tsunami: A Post-Event Survey of the Coastal Effects

The paper is a report of the field campaign undertaken by an international team (Italian, French and Indonesian) a few weeks after the occurrence of a tsunami invading the south-eastern coast of Java (Indonesia) and it complements the results of a concurrent field survey by Asian and USA researchers. The tsunamigenic earthquake occurred on 3 of June 1994 in the Indian Ocean about 200 km south of Java. The tsunami caused severe damage and claimed many victims in some coastal villages. The main purpose of the survey was to measure the inundation and the runup values as well as to ascertain the possible morphological changes caused by the wave attacks. Attention was particularly focussed on the most affected districts, that is Lumajang, Jember and Banyuwangi in Java, although also the districts of Negera, Tebanan and Denpasar in Bali were examined. The most severe damage was observed in the Banyuwangi district, where the villages of Rajekwesi, Pancer and Lampon were almost completely levelled by the violent waves. Most places were hit by three significant waves with documented wave height often exceeding 5 m. The maximum runup value (9.50 m) was measured at Rajekwesi, where also the most impressive erosion phenomena could be found. In contrast, only in one place of the neighbouring island of Bali was there a slight tsunami, the rest of the island being practically unaffected.     

上海地区场地剪切波速的特征分析

通过对上海地区场地剪切波速资料的统计分析,较深入地探讨了上海地区场地剪切波速在100m深度内的分布范围及其变化规律,可在工程实践中参考使用。     

丽江地震区应力场研究

通过现场调查工作,研究了丽江地区主要活动断裂的特征及现代活动性,分析了该地区构造应力场演化历史及现今构造应力场特征,探讨了丽江地震产生的机制,然后用离散元方法对该地区现今应力场进行了二维模拟,并进而深化了对丽江地震区应力场的认识。丽江地区处于川滇菱形断块的西南部,巨甸-九子海断块二级断块中的玉龙雪山-九子海三级断块上,该断块介于近南北向的楚波-白汉场断裂、北东走向丽江-小金河断裂和北西向中甸-永胜断裂之间,平面上成一顶角向东的三角形。在近南北向现今应力场的作用下,北东向的丽江-小金河断裂左旋走滑,北西向的中甸一永胜断裂右旋走滑,使两者所夹持的巨甸-九子海断块的主体部分发生向西的位移,在两者的复合部位,即断块的尖端附近,形成了局部的近东西向的拉张应力环境,从而使处于该部位的南北向玉龙雪山东麓断裂于1996年2月3日因发生了正断错动而导致了7．0级地震的发生。该地震后第三天,在其震中的正南方又发生了一次6．0级余震,其地震破裂是由北向南的一种撕裂,进而说明,本次地震的发生是由于玉龙雪山东麓断裂与中甸一永胜断裂复合部位拉张应力的强烈集中造成的。     

地震超剪切破裂研究现状

地震断层的破裂速度是地球物理学和地震学研究中重要的一个参数,以往的相关研究多是基于或者关注于断层破裂速度小于或接近于剪切波速时的情况,但是随着宽频带地震学的发展,在实际地震中已经观测到了一些超剪切波破裂速度的地震.为了解地震超剪切破裂相关研究的现状和发展趋势,基于大量相关研究文献,从地震超剪切破裂的概念、断层的极限破裂...     

The Behaviour of a Man-Made Island During the Great Hanshin Earthquake,Japan

This paper describes the behaviour of Port Island in Kobe city during and after the Great Hanshin Earthquake of 17 January 1995. The island is near the city centre and was constructed on the soft seabed in Kobe Port. A vertical array of four seismometers and pore water pressure sensors recorded the response of the ground during and after the earthquake. This study shows how the stiffness of the ground dropped and recovered during and after the earthquake.     

构造成图时深转换方法

绝大多数地震资料构造解释是在时间域完成的,而地质人员使用的资料为深度域资料,因此时深转换必不可少。时深转换有多种方法,不同方法的应用范围不同,复杂程度各异。本文对各类时深转换方法流程进行了详细叙述,并对常用时深转换方法适用的地质条件进行了阐述。通过对实际油田时深转换方法的运用发现,时深拟合法对浅层速度横向变化较小的地层进行时深转换所得构造相对误差小于2‰,表明时深拟合法对该类地层时深转换精度高;对于有速度异常地层、速度横向变化较大地层时深转换时,选择合适的方法也能有效提高构造成果准确度。描述了各类时深转换方法的优缺点,由于地震资料本身分辨率及速度精度的限制,根据不同的地质情况,选择合适的时深转换方法,才能提高构造成果的精度,减少地质认识风险。     

Distribution Survey of Soils in the Hainan Island and Their Physico-mechanical Properties

This paper from the point of regional, based on the statistics and analyses on a great number of geotechnical test, deals with the geneses and composition of Hainan soils and the distribution law of various soils in the Hainan Island, the physico-mechanical properties of the soils are also discussed in the paper. All this is the summary on the work during the past three decades. The research results listed in the paper can be used to a certain extent as a reference for the development of the Hainan Island.     

海南岛土类的分布概况及物理力学特性

本文对以往三十来年的工作进行了总结,在统计和分析大量的土工试验资料的基础上,从区域土质学的观点出发,研究了海南岛土类的成因、成份及各种土类的分布规律,探索了各类土的物理力学特性。文中所列的海南岛各种土类的物理力学试验研究成果,对今后海南岛的进一步开发有一定的参考价值。