usgs-global-earthquake-catalog

# USGS Global Earthquake Catalog

Provides historical data on global seismic events, sourced directly from the U.S. Geological Survey (USGS) Earthquake Hazards Program via its FDSN Event Web Service.

Each record represents a single seismic event (primarily earthquakes) and contains detailed information, including:

1. **Event Time & Location**: Precise timestamp, geographic coordinates (`latitude`, `longitude`), and depth of the event.

2. **Magnitude**: The magnitude of the event (`mag`) and the method used to calculate it (`magType`), such as `md`, `ml`, or `mww`.

3. **Data Quality**: Metrics such as root mean square (`rms`) of travel-time residuals, azimuthal gap (`gap`), and measurement errors to assess the reliability of the data.

4. **Source Information**: Details about the network (`net`) that reported the event and a unique event ID.

# 美国地质调查局全球地震目录
本数据集收录全球地震事件的历史观测数据，直接来源于美国地质调查局（U.S. Geological Survey, USGS）地震灾害项目的FDSN事件网络服务（FDSN Event Web Service）。

每条记录对应单个地震事件（以天然地震为主），并包含详细的属性信息，具体如下：
1. **事件时间与位置**：精确的事件发生时间戳、地理坐标（纬度`latitude`、经度`longitude`）以及震源深度。
2. **震级参数**：事件震级`mag`及其计算方法`magType`，例如`md`、`ml`或`mww`。
3. **数据质量指标**：用于评估数据可靠性的各类参数，包括走时残差的均方根`rms`、方位角间隙`gap`以及测量误差。
4. **来源信息**：报告该事件的台网`net`以及唯一事件标识符。