January - April 2024 Ionian islands Swarm-like excitation relocated earthquake catalog

1. Introduction This dataset comprises the relocated earthquake catalog of 7420 earthquakes for the period 2024-01-01 to 2024-04-30 for the Myrtos gulf area north of Kefalonia island, where a swarm-like excitation took place, intensifying during the February - April 2024 period. Phase picking was performed using the Phasenet (Zhu and Beroza, 2019) deep-learning picker and picks were associated using the REAL associator (Zhang et al., 2019). The events were initially located using HYPOINVERSE (Klein, 2002) and relocated using catalog differential times using HypoDD (Waldhauser and Ellsworth, 2000). The seismic velocity model used for the location and relocation procedures is taken from Haslinger et al. (1999). Magnitudes were estimated by applying the relation proposed by Scordilis et al. (2016). 2. Files 2.1 Relocated catalog (catalog_ionio24_swarm.csv, catalog_ionio24_swarm.xlsx and catalog_ionio24_swarm.xml) The dataset consists of the relocated catalog, provided in three different formats (.csv, .xlsx, QuakeML). Arrivals and picks are included within the QuakeML catalog. Field descriptions in the .csv and .xlsx files are as follows: · event_id: Sequential event ID number · latitude: Latitude of relocated epicenter · longitude: Longitude of relocated epicenter · depth: Depth of relocated earthquake · year, month, day, hour, minute, seconds: Temporal origin parameters · magnitude: Earthquake magnitude · magnitude_type: Earthquake magnitude type · RMS: RMS of the travel time residuals of the arrivals used for the origin computation. · ErrH: Horizontal error · ErrZ: Depth error · P_count: Number of defining P phases, i.e., phase observations that were actually used for computing the origin. · S_count: Number of defining P phases, i.e., phase observations that were actually used for computing the origin. · Phases_total: Total number of defining phases The QuakeML catalog follows the modular XML seismological standard schema, extensively described in the QuakeML manuals. 2.2 Phase file (catalog_ionio24_swarm_phases.txt) Standalone phase file used for compiling the relocated catalog in HypoDD format, containing absolute travel time data information for P and S arrivals. File format is described in the HypoDD user guide. 2.3 Stationxml files (Stationxml.tar) Stationxml files used for the preprocessing procedure before phase picking, for the study period.1. 概述 本数据集涵盖了2024年1月1日至2024年4月30日期间，凯法洛尼亚岛北部米尔托斯湾区域的7420次地震的重定位地震目录。该区域曾发生类群震活动，且在2024年2月至4月期间活动强度显著增强。 本次研究的震相拾取采用Phasenet（Zhu与Beroza，2019）深度学习拾取器完成，拾取结果通过REAL震相关联器（Zhang等，2019）进行关联。地震事件首先使用HYPOINVERSE（Klein，2002）进行初始定位，随后借助HypoDD（Waldhauser与Ellsworth，2000）基于目录差分时间完成重定位。本次定位与重定位所采用的地震速度模型源自Haslinger等（1999）的研究成果。地震震级则通过应用Scordilis等（2016）提出的计算公式进行估算。 2. 文件 2.1 重定位地震目录（catalog_ionio24_swarm.csv、catalog_ionio24_swarm.xlsx及catalog_ionio24_swarm.xml） 本数据集提供了三种格式的重定位地震目录：.csv、.xlsx与QuakeML格式。QuakeML格式的目录中包含了震相到时与拾取结果。.csv与.xlsx文件的字段说明如下： · event_id：连续式事件标识编号 · latitude：重定位后震中的纬度坐标 · longitude：重定位后震中的经度坐标 · depth：重定位后的地震震源深度 · year、month、day、hour、minute、seconds：发震时刻的各项时间参数 · magnitude：地震震级 · magnitude_type：地震震级类型 · RMS：用于发震时刻计算的到时走时残差的均方根值 · ErrH：震中水平方向的定位误差 · ErrZ：震源深度方向的定位误差 · P_count：用于发震时刻计算的有效P波震相观测数量 · S_count：用于发震时刻计算的有效S波震相观测数量（原文此处存在笔误，原标注为P波，已按专业逻辑修正） · Phases_total：本次计算所使用的全部有效震相总数 QuakeML格式目录遵循模块化XML地震学标准规范，相关细节可参考QuakeML官方手册。 2.2 震相文件（catalog_ionio24_swarm_phases.txt） 该独立震相文件用于以HypoDD格式编译重定位目录，包含P波与S波到时的绝对走时数据信息。文件格式可参考HypoDD用户指南。 2.3 台站XML文件（Stationxml.tar） 该台站XML文件集合用于本次研究时段内震相拾取前的预处理流程。