According to the requirements of Earthquake Emergency Service Response Level (Interim) of China Earthquake Administration, when an earthquake of M ≥ 7.0 occurs in densely populated areas and an earthquake of M ≥ 6.0 occurs in Beijing-Tianjin-Hebei area, large cities in the Yangtze River Basin, Pearl River Delta and provincial capitals, Level 1 emergency service response will be activated. When an earthquake of 6.0 ≤ M < 7.0 occurs in densely populated areas or an earthquake of 5.0 ≤ M < 6.0 occurs in Beijing-Tianjin-Hebei, large cities in the Yangtze River basin, Pearl River Delta and provincial capitals, level II emergency services shall be activated. According to the requirements of the “List of primary and secondary response actions for post-earthquake emergency services of the China Earthquake Administration within 12 h after the earthquake”, the Department of Science and Technology of the China Earthquake Administration starts the scientific investigation within 8–12 h after the earthquake and organizes the preparation of the plan of earthquake scientific investigation (referred to as “earthquake investigation”).