The HELPOS Fault Database: a new contribution to seismic hazard assessment in Greece

In seismically-active regions such as Greece, the mapping of active faults is a key step to assess seismic hazards and evaluate deterministic ground motion scenarios for infrastructure works, pipeline designs and other constructions of critical importance. Here, we present a comprehensive database of active onshore and offshore faults in Greece based on existing studies and GIS geospatial mapping using geological, geophysical, seismological and geomorphological criteria. The design and population of the database follows the NOAFaults concept http://doi.org/10.5281/zenodo.3483136 and development in ARCGIS environment. The HELPOS database includes over 550 faults with simplified (linear) traces and lengths between 8 – 108 km (onshore part) together with their corresponding 2D rupture planes. Additional information includes parametric data such as maximum expected magnitude, slip rate, length, width, strike, dip angle, last seismic event, rupture depth (to top-fault) and fault kinematics. A particular aim of the HELPOS Fault database has been an update of the seismic sources model for the seismic hazard assessment of Greece considering shallow earthquakes, which involves modeling surface fault traces in terms of seismic sources at depth. The fault database is a major contribution to HELPOS with applications among others in volcano-tectonic settings, urban planning, paleoseismology, landscape processes, and in the study of active tectonics, deformation and interactions between overriding plate (Aegean) faults and the Hellenic subduction. <strong>In this version of the database (v1.8) we include the onshore fault traces and rupture planes and the offshore fault traces</strong>. We acknowledge funding by project "HELPOS - Hellenic Plate Observing System” (MIS 5002697) which was funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund).在地震活跃区域（如希腊），活动断层（active faults）填图是评估地震危险性（seismic hazards）、为基础设施工程、管线设计及其他重大建构筑物确定确定性地震动场景（deterministic ground motion scenarios）的关键环节。 本研究依托已有研究成果，结合地质、地球物理、地震学与地貌学准则开展地理信息系统（GIS）地理空间填图，构建了覆盖希腊陆域与海域的活动断层综合数据库。 本数据库的设计与数据录入遵循NOAFaults标准框架（http://doi.org/10.5281/zenodo.3483136），并基于ArcGIS环境开发完成。 HELPOS数据库共收录超过550条活动断层，陆域断层的简化（线性）迹线长度介于8至108千米之间，并配套对应的二维破裂平面。 数据库还包含多类参数化属性数据，如最大预期震级、滑动速率、断层长度、宽度、走向、倾角、末次地震事件、破裂深度（至断层顶面）以及断层运动学（fault kinematics）特征。 HELPOS活动断层数据库的核心目标之一，是针对浅源地震更新希腊地震危险性评估所用的震源模型——该模型需基于地表断层迹线，构建深部震源的模拟表达。 本断层数据库是HELPOS项目的重要成果之一，可应用于火山构造环境（volcano-tectonic settings）研究、城市规划、古地震学（paleoseismology）、地表过程研究，以及活动构造、变形作用与上覆板块（爱琴海板块）断层和Hellenic俯冲带之间相互作用的相关研究。 **在本数据库v1.8版本中，我们纳入了陆域断层迹线、破裂平面及海域断层迹线**。 本研究感谢“HELPOS——希腊板块观测系统”项目（项目编号MIS 5002697）的资助，该项目隶属于“竞争力、创业与创新”运营计划（NSRF 2014-2020），由希腊与欧盟（欧洲区域发展基金）共同出资。