POSTSEISMIC GPS SURVEY, MODELING, AND EDUCATION FOLLOWING THE M7.0 JANUARY 12, 2010 EARTHQUAKE IN HAITI

2010年1月12日，7级地震袭击了海地太子港地区，造成约230,000人死亡，150多万人无家可归，损失占海地国内生产总值的120%-S，摧毁了这个拥有300万人口的地区的大部分政府、技术和教育基础设施。尽管地球科学界警告说，海地发生地震的风险很高，但该国发现自己没有做好准备。鉴于历史地震活动表明，这次地震可能是新一轮大事件的开始，必须了解未来几年地震危险最大的地方，并使海地人民为这一可能发生的情况做好准备。为此，我们将测量震后变形，以限制应力传递的数字模型，并制定海地特有的地震教育课程，供海地高中使用。具体地说，该项目将(1)利用现有连续GPS站和我们在1月份地震后立即安装和观察的测量站点相结合，测量震后三维形变；(2)利用这些约束来验证震后变形的有限元模型，并推断三种主要震后机制：余滑、孔洞弹性回弹和粘弹性松弛的相对贡献和深度分布；以及(3)使用产生的有限元模型来计算区域断层在未来几年内库仑应力的演变，以确定哪些段目前以最快的速度加载。1月份的地震是北加勒比板块在大地年龄内发生的第一次大事件，因此为利用震后观测探索该地区下地壳和上地幔的流变性提供了一个关键机会。这项工作对于了解板块边界的扭压如何在深处得到调节，以及更重要的是，地震后过程目前如何改变该地区其他活动断裂上的应力场是至关重要的。因此，这项工作将有助于提高我们对1月12日地震后海地地震相关危险的了解，并有助于确定沿该断层系统可能发生其他大地震的可能性。该项目启动了海地非常需要的地球科学能力建设工作，包括对海地合作者进行使用现代空间大地测量技术的培训，并对海地的S·杨进行教育。在进行GPS工作的同时，我们将访问我们经过的城镇中的海地高中，讨论海地的构造和地震危险。此外，我们将与美国和海地的高中教师和学生合作，与无国界教师组织合作，开发海地高中使用的地震教育课程。该课程将侧重于区域构造、地震灾害以及海地特有的准备和规划工作，以创造持久的地震教育遗产。

On January 12, 2010 a Mw7 earthquake struck the Port-au-Prince region of Haiti, killing an estimated 230,000 people, leaving more than 1.5 million homeless, costing 120% of the country?s GDP, and destroying most governmental, technical, and educational infrastructure throughout this region of 3 million people. Despite warnings from the geoscience community that Haiti was at high risk for an earthquake, the country found itself unprepared. With historical seismicity indicating that this earthquake may be the beginning of a new cycle of large events, it is imperative to understand where seismic hazards are greatest in the years to come, and to prepare the people of Haiti for this eventuality. To this end we will measure postseismic deformation to constrain numerical models of stress transfer and develop a Haiti-specific earthquake education curriculum for use in Haitian high schools. Specifically, this project will (1) measure 3-dimensional postseismic deformation using a combination of existing continuous GPS stations and survey sites that we installed and observed immediately following the January earthquake; (2) use these constraints to validate finite element models of postseismic deformation and infer the relative contributions and depth distributions of the three main postseismic mechanisms: afterslip, poroelastic rebound, and viscoelastic relaxation; and (3) use the resulting finite element models to calculate the evolution of Coulomb stress on regional faults in the years to come to determine which segments are currently being loaded at the fastest rates. The January earthquake is the first large event to occur in the northern Caribbean plate within the geodetic age, and thus provides a key opportunity to use postseismic observations to explore the rheological properties of the lower crust and upper mantle in this region. This work is critical to understanding how transpression at this plate boundary is accommodated at depth, and more imperatively, how postseismic processes are currently working to change the stress field on other active faults in the region. Thus, this work will help to improve improving our understanding of the hazards associated with earthquakes in Haiti following the January 12 event and help define the likelihood that other large earthquakes may be impending along that fault system. The project initiates a capacity building effort in geosciences that is so much needed in Haiti, including the training of Haitian collaborators in the use of modern space geodetic techniques and the education of Haiti?s young. While conducting our GPS work, we will visit Haitian high schools in the towns we pass through to discuss the tectonics and earthquake hazards of Haiti. In addition, we will work with US and Haitian high school teachers and students, in collaboration with Teachers Without Borders to develop an earthquake education curriculum for use in Haitian high schools. The curriculum will focus on regional tectonics, earthquake hazards, and preparedness and planning efforts specific to Haiti in order to create a lasting legacy of earthquake education.