International Collaboration and Training for the Assessment and Mitigation of Seismic Hazard in Iran

伊朗是世界上地震最多发的国家之一。在过去50年中，发生了5次大地震，每次都造成1万多人死亡，最近一次是2003年12月摧毁巴姆市的地震。几乎每年都有地震对人员和财产造成重大损害，例如2005年2月发生的扎兰德地震。试图减少地震造成的损失的第一步是评估在给定地区发生地震的可能性。地震是由于地壳内断层的滑动而发生的。它们是由断层两侧地壳块体的相对运动引起的。最初，摩擦力使断层锁定;然而，随着时间的推移，断层两侧岩石的弯曲程度不断增加，直到它施加的力克服了断层上的摩擦力。断层两侧的岩石相对于彼此快速滑动，辐射出地震波，导致附近地面剧烈震动。可以进行一些观测来评估未来地震的可能性。确定所有活断层的位置是一个重要的起点。在伊朗这样的国家，这并不像看起来那么容易，因为许多断层没有到达地表，而是隐藏在地下。然而，在过去的地震中，地球表面的运动在陆地表面产生了特征性的特征，特别是断层周围的溪流和河流的模式，这些特征可以让我们找到以前没有被认识到的断层。绕地球轨道运行的卫星上的仪器进行的测量在这一研究中起着重要作用。全球定位系统中的卫星可用于测量微小的运动-每年几毫米到几厘米-因此使我们能够检测断层周围岩石的弯曲。使用雷达卫星的重复观测也测量了地震之间发生的缓慢地面运动。估计过去地震发生频率的最有效方法是将联合收割机卫星测量与在危险地区进行的地面地质观测结合起来。为伊朗开展广泛的此类测量方案是一项艰巨的任务。伊朗地质调查局（GSI）是负责评估伊朗地震灾害的主要机构，但它缺乏开展这一方案的专门知识。然而，地震和构造观测和建模中心（COMET）的成员是这类观测的专家，COMET的调查人员多年来一直与地质科学研究所合作，研究造山（构造）和地震科学的许多方面。因此，这项建议的目的是将伊朗年轻科学家带到联合王国，在那里他们将在彗星内部接受适当技术的培训，并通过与彗星成员合作向他们学习。建议的另一部分是召开一次国际会议，召集几个此类国家的地质学家和地震学家，他们将根据观测结果进行灾害评估，并与规划大地震和减轻其影响有关的人员，以便分享经验，并制定一种共同的办法，将我们的结果传达给当地社区和区域当局。教育在减轻大地震影响方面的作用不可低估。就最近苏门答腊近海发生的大地震（2004年12月26日）而言，过去该地区曾发生过此类地震，这一点已得到充分承认，而且人们也了解此类地震将产生的影响。如果这一信息成功地传达给当地社区和地区当局，那么，虽然地震无法预测或预防，但其破坏性后果可能会大大减少。

Iran is one of the most earthquake-prone countries in the world. In the past 50 years, there have been five major earthquakes that have each killed more than 10,000 people, the most recent being the earthquake that devasted the city of Bam in December 2003. Almost every year there is an earthquake that does significant damage to people and property, e.g. the Zarand earthquake that occurred in February 2005. The first step in attempting to reduce the damage caused by earthquakes is to assess the likelihood of an earthquake occurring in a given area. Earthquakes occur by slip on faults within the earth's crust. They are caused by the relative motion of crustal blocks on each side of the fault. Initially friction holds the fault locked; however, with time, the bending of the rocks either side of the fault grows until it exerts a force that overcomes the friction on the fault. The rocks on either side of the fault then slip rapidly relative to each other radiating seismic waves and causing severe shaking of the ground nearby. A number of observations can be made to assess the likelihood of a future earthquake. Locating all the active faults is an essential starting point. This is not as easy as it might seem in a country like Iran where many of the faults do not reach the surface and remain hidden below ground. However, movement of the earth's surface in past earthquakes produces characteristic features in the land surface, particularly the pattern of streams and rivers around the fault, and these features can allow us to find faults whose existence had not previously been recognized. Measurements made by instruments on satellites orbiting the earth play an important role in this search. The satellites in the Global Position System can be used to measure small movements - a few millimetres to a couple of centimetres per year - and so allow us to detect the bending of rocks around the faults. Repeated observations using radar satellites also measure the slow ground motions occurring in between earthquakes. The most effective way to estimate how frequently earthquakes have occurred in the past is to combine satellite measurements with geological observations made on the ground in areas at risk. The task of carrying out an extensive programme of such measurements for Iran is a huge one. The Geological Survey of Iran (GSI) is the primary agency with responsibility for assessing earthquake hazard in Iran, but it lacks the expertise to undertake such a programme. However, the members of the Centre for the Observation and Modeling of Earthquakes and Tectonics (COMET) are expert in these types of observation, and COMET investigators have worked for many years with the GSI on many aspects of the science of mountain building (tectonics) and earthquakes. The purpose of this proposal is therefore to bring young Iranian scientists to the UK, where they will be trained within COMET in the appropriate techniques and learn from members of COMET by working with them. Another part of the proposal is for an international meeting that would bring together geologists and geophysicists making the observations on which the hazard assessment is based, and people concerned with planning for major earthquakes and mitigating their impact, from several such countries in order to share experiences and develop a common approach to communicating our results to local communities and regional authorities. The role of education in reducing the impact of major earthquakes is not to be underestimated. In the case of the recent large earthquake off Sumatra (26/12/2004), the existence of such earthquakes in that region in the past were well recognized and the effects that such an earthquake would produce were understood. If this information had been successfully communicated to local communities and to regional authorities, then, while the earthquake could not have been predicted or prevented, its damaging after effects could have been significantly reduced.