L'Aquila 2009 seismic sequence: integrated dataset of automatic first motion polarities focal mechanisms and RMT with HypoDD high quality relative earthquake locations
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This dataset is related to the L'Aquila 2009 seismic sequence that happened in Central Apennines (Italy). It contains: 2782 quality selected focal mechanisms produced with the standard software FPFIT based on automatically determined first motion polarities of automatically detected and analyzed foreshocks and aftershocks recorded from January 2009 to December 2009 (flag <strong>fty</strong> in the header is MP) 475 (out of 627) quality selected focal mechanisms produced with the standard software FPFIT also based on automatically determined first motion polarities but for only 3204 M<sub>L</sub> >= 1.9 earthquakes and by using take-off angles calculated within a local 3d tomographic velocity model (Di Stefano et al., 2011) , published and released in Chiaraluce et al., 2011 (flag <strong>fty</strong> in the header is JG) 165 (out of 181) Regional Moment Tensors determined for earthquakes M<sub>L</sub> >= 3.0 based on broadband waveform inversion of ground velocities and published by Hermann et al., 2011 (flag <strong>fty</strong> in the header is HM) The hypocenters of the total 3422 earthquakes reported in the present focal solutions dataset have been taken from the very high quality double difference locations of the about 64000 aftershocks reported in Valoroso et al., 2013 and published, as part of the full dataset, on Zenodo. The association between the focal solutions and the HypoDD hypocenters has been performed through the direct use of the HypoDD event identifier where possible (the whole MP dataset) and through spatial and temporal earthquakes coordinates matching in all the other case by using the capability of a MySQL database. Two files are uploaded, one in plain text with blank separator, the second in plain text with ";" separator and .csv extension. Here below the header is explained. <strong>OT_Date:</strong> date of the origin time in the format YYYY-MM-DD <strong>OT_Time:</strong> time of the origin time in the format HH:mm:ss.dcm <strong>lat:</strong> hypocenter latitude expressed in degrees <strong>lon:</strong> hypocenter longitude east of Greenwich, expressed in degrees <strong>dep:</strong> hypocenter depth expressed in km <strong>ML:</strong> local magnitude (pure number) from Valoroso et al., 2013 (see last column notes also) <strong>id_dd:</strong> the hypoDD event identifier, allowing to directly connect to the Valoroso et al., 2013 full dataset <strong>IMPORTANT NOTE about st1 and st2 (below): </strong>the focal solutions are presented here based on the convention they where produced or published, so there are two different (but compatible) conventions for the fault plains orientation in the 3d space <strong>st1:</strong> <strong>for fty=</strong>HM or JG this is the strike of plane 1 (CMT convention) <strong>for fty=</strong>MP this is the <strong>strike of the dip direction </strong>of plain 1 (FPFIT convention) <strong>dip1: </strong>dip of plane 1 <strong>rk1: </strong>rake of plane 1 <strong>st2:</strong> <strong>for fty=</strong>HM or JG this is the strike of plane 2 (CMT convention) <strong>for fty=</strong>MP this is the <strong>strike of the dip direction </strong>of plain 2 (FPFIT convention) <strong>dip2: </strong>dip of plane 2 <strong>rk2: </strong>rake of plane 2 <strong>fty:</strong> flag to distinguish the type of solution, CMT=HM or JG, FPFIT=MP <strong>MW:</strong> only for HM, this columns reports also MW from Hermann et al., 2011
本数据集关联于2009年意大利亚平宁中部发生的拉奎拉（L'Aquila）地震序列。数据集包含以下内容： 1. 2782件经品质筛选的震源机制（focal mechanisms），采用标准软件FPFIT生成，基于2009年1月至12月间自动检测与分析的前震（foreshocks）、余震（aftershocks）的自动确定初动极性（first motion polarities），文件头中<strong>fty</strong>标记为MP； 2. 627件地震中筛选出的475件高品质震源机制，同样采用标准软件FPFIT生成，基于自动确定的初动极性，但仅针对3204件M_L≥1.9的地震，并使用基于当地三维层析成像速度模型（3D tomographic velocity model）（Di Stefano等，2011）计算的出射角（take-off angles），该数据集已发表于Chiaraluce等，2011，文件头中<strong>fty</strong>标记为JG； 3. 181件地震中筛选出的165件区域矩张量（Regional Moment Tensors），针对M_L≥3.0的地震，基于地面速度的宽频带波形反演（broadband waveform inversion）得到，由Hermann等，2011发表，文件头中<strong>fty</strong>标记为HM。 本震源解（focal solutions）数据集中共记录的3422次地震的震源位置（hypocenters），取自Valoroso等，2013中约64000次余震的高品质双差定位（double difference locations）结果，该完整数据集已作为公开数据集发布于Zenodo。 震源解与HypoDD震源位置的关联，在全部MP数据集下直接使用HypoDD事件标识符，其余情况则通过MySQL数据库的时空地震坐标匹配完成。 本次上传包含两个文件，其一为以空格分隔的纯文本文件，其二为以分号分隔、后缀为.csv的纯文本文件。下文将对文件头字段进行解释： <strong>OT_Date:</strong> 发震时刻日期，格式为YYYY-MM-DD <strong>OT_Time:</strong> 发震时刻时间，格式为HH:mm:ss.dcm <strong>lat:</strong> 震源纬度，单位为度 <strong>lon:</strong> 震源经度（格林威治以东），单位为度 <strong>dep:</strong> 震源深度，单位为千米 <strong>ML:</strong> 局部震级（纯数值），取自Valoroso等，2013（详见最后一列注释） <strong>id_dd:</strong> HypoDD事件标识符，可直接关联至Valoroso等，2013的完整数据集 <strong>IMPORTANT NOTE about st1 and st2 (below):</strong> 关于st1与st2的重要说明： 本数据集的震源解按照其生成或发表时所采用的坐标系惯例呈现，因此针对三维空间中断层平面取向存在两种兼容的坐标系惯例： <strong>st1:</strong> 当<strong>fty=HM或JG</strong>时，该字段表示平面1的走向（strike），遵循CMT约定； 当<strong>fty=MP</strong>时，该字段表示平面1的倾向方向的走向，遵循FPFIT约定 <strong>dip1:</strong> 平面1的倾角（dip） <strong>rk1:</strong> 平面1的滑动角（rake） <strong>st2:</strong> 当<strong>fty=HM或JG</strong>时，该字段表示平面2的走向（strike），遵循CMT约定； 当<strong>fty=MP</strong>时，该字段表示平面2的倾向方向的走向，遵循FPFIT约定 <strong>dip2:</strong> 平面2的倾角（dip） <strong>rk2:</strong> 平面2的滑动角（rake） <strong>fty:</strong> 用于区分震源解类型的标记：CMT对应HM或JG，FPFIT对应MP <strong>MW:</strong> 仅适用于HM类型数据，该列同时包含Hermann等，2011中给出的矩震级（M_W）。
