Réunion
Réunion is located in Africa and has a Low seismic risk classification. A total of 1 earthquakes have been recorded in the country's seismic history. The largest earthquake recorded in the country reached a magnitude of 5.0. With a population of 896,175 and a land area of 2,511 km², seismic events can have significant implications for infrastructure and public safety.
Seismic Overview
Réunion is a French overseas department in the Indian Ocean, approximately 700 kilometres east of Madagascar, and one of the world's most volcanically active islands. The island is built entirely on the Réunion hotspot — the same mantle plume responsible for the Deccan Traps flood basalts and the Chagos-Laccadive Ridge. The hotspot is currently active beneath the southeastern part of the island, where the Piton de la Fournaise shield volcano erupts an average of once or twice per year. The northwestern part of the island is dominated by the older, extinct Piton des Neiges massif, which reaches 3,069 metres — the highest point in the Indian Ocean.
Seismicity at Réunion is dominated by volcano-tectonic activity beneath Piton de la Fournaise. Each eruptive episode is preceded and accompanied by hundreds to thousands of small [[seismic-wave]] events as magma forces its way through the volcanic edifice. These volcanic earthquakes are shallow — typically less than 5 kilometres deep — and rarely exceed [[magnitude]] 3.5 at the surface. Tectonic seismicity is minor; the island sits on the relatively stable interior of the Indo-Australian Plate, and no active tectonic faults are mapped beneath it.
The primary hazard beyond volcanic earthquakes is [[tsunami]]. Réunion's coastlines are vulnerable to locally generated waves if a large volcanic flank collapse occurred on Piton de la Fournaise — a concern supported by massive ancient underwater landslide deposits on the eastern submarine slope. The 2004 Indian Ocean [[tsunami]] reached Réunion but caused only minor wave heights due to offshore bathymetric geometry. The REVOSIMA and IPGP observatories operate comprehensive [[seismograph]] networks for continuous monitoring of volcanic and tectonic signals.
Recent Earthquakes
| Mag | Location | Time | |
|---|---|---|---|
| No recent earthquakes. | |||
Frequently Asked Questions
Réunion has a low level of seismic activity. Large earthquakes are infrequent but not impossible. A total of 1 earthquakes have been recorded in Réunion's seismic history.
The largest recorded earthquake in Réunion had a magnitude of 5.0. Earthquakes of this size can cause significant damage depending on depth, location, and local building standards.
Réunion has had 1 recorded earthquakes. This count includes events of all magnitudes detected by seismic monitoring networks. The actual number of earthquakes may be higher, as smaller events can go undetected.
Réunion is classified in the "Low" seismic zone, located in Africa. Seismic zones indicate the relative level of earthquake hazard based on historical activity, geological conditions, and proximity to tectonic plate boundaries.
During an earthquake, Drop, Cover, and Hold On. Get under a sturdy desk or table, protect your head and neck, and hold on until shaking stops. Move away from windows and heavy objects. After the earthquake, check for injuries and be prepared for aftershocks.
Country earthquake risk is assessed using several factors: proximity to tectonic plate boundaries, historical seismicity (frequency and magnitude of past events), geological conditions, population density in seismic zones, and building code enforcement. QuakeFYI assigns seismic zones from 0 (no risk) to 4 (very high) based on these factors.
A seismic zone is a geographic area classified by the level of earthquake hazard. Zone 0 has negligible risk, Zone 1 has low risk, Zone 2 has moderate risk, Zone 3 has high risk, and Zone 4 has very high risk. These zones are determined by historical earthquake data, tectonic setting, and geological conditions.
Countries along the Pacific Ring of Fire experience the most earthquakes. Japan, Indonesia, Chile, the Philippines, and Iran consistently record the highest seismic activity. The United States (especially Alaska and California), Turkey, and Mexico are also among the most seismically active nations.
Population density amplifies earthquake risk because more people and infrastructure are exposed to potential damage. A magnitude 7.0 earthquake in a densely populated city can cause thousands of casualties, while the same event in an uninhabited area may cause none. Building codes and emergency preparedness greatly reduce risk in populated areas.
Seismic density measures the concentration of earthquake activity relative to a country's land area, expressed as earthquakes per 1,000 square kilometers. A high seismic density indicates frequent earthquake activity per unit area, helping compare seismic risk between countries of different sizes.