Saint Pierre and Miquelon
Saint Pierre and Miquelon is located in North America and has a Low seismic risk classification. A total of 12 earthquakes have been recorded in the country's seismic history. The largest earthquake recorded in the country reached a magnitude of 5.1. With a population of 5,819 and a land area of 242 km², seismic events can have significant implications for infrastructure and public safety.
Seismic Overview
Saint Pierre and Miquelon is a French overseas collectivity in the northwestern North Atlantic, consisting of two small archipelagos located approximately 25 kilometres south of the Burin Peninsula of Newfoundland, Canada. The territory sits on the North American Plate, geologically continuous with the Appalachian fold belt and the ancient continental margin of eastern Canada. There are no active plate boundaries in the immediate vicinity: the nearest active tectonic feature is the mid-Atlantic Ridge system, which lies more than 2,000 kilometres to the east. The primary geological context is the ancient rifted margin of eastern North America, which underwent passive continental breakup during the Mesozoic and has been seismically quiescent at the plate-boundary scale ever since. Some residual intraplate seismicity occurs in the Canadian Maritime and Newfoundland region, associated with post-glacial isostatic rebound and ancient reactivated faults in the Appalachian basement. Seismic hazard at Saint Pierre and Miquelon is rated low.
The earthquake history of Saint Pierre and Miquelon consists primarily of felt events from regional eastern Canadian and Grand Banks sources. The territory has no record of a locally destructive earthquake. The 1929 Grand Banks earthquake (magnitude 7.2), centred approximately 250 kilometres south of Newfoundland, was strongly felt in Saint Pierre and generated a devastating [[tsunami]] that struck the south coast of Newfoundland, killing 28 people — the only [[tsunami]] deaths in Canadian history. Wave effects were likely felt in Saint Pierre given its proximity to the source. The 1755 Lisbon earthquake [[tsunami]], one of the most powerful in Atlantic history, generated waves that were detected along the entire eastern seaboard of North America; Saint Pierre would have been within the wave propagation path. Occasional M3–4 intraplate earthquakes from the Newfoundland platform and Laurentian Slope are recorded in the instrumental era.
Saint Pierre and Miquelon's bedrock consists of Paleozoic metamorphic and sedimentary rocks of the Appalachian belt — slates, quartzites, and greywackes — overlain by thin Quaternary glacial deposits. The islands were extensively glaciated during the Pleistocene, and the landscape retains classic glacially abraded features. Post-glacial rebound is ongoing at a modest rate in the sub-arctic Maritime region, contributing to minor intraplate stress. The territory's seismic risk is dominated by the [[tsunami]] hazard from potential earthquake sources along the Newfoundland margin and from large Atlantic submarine landslides rather than from local fault rupture. Seismic monitoring in the region is conducted by Natural Resources Canada's national seismograph network, which provides regional coverage of the Maritime and offshore Newfoundland zone.
Recent Earthquakes
| Mag | Location | Time |
|---|---|---|
| 3.1 | 16 km SE of Miramichi, Canada | 2 weeks, 6 days ago |
Frequently Asked Questions
Saint Pierre and Miquelon has a low level of seismic activity. Large earthquakes are infrequent but not impossible. A total of 12 earthquakes have been recorded in Saint Pierre and Miquelon's seismic history.
The largest recorded earthquake in Saint Pierre and Miquelon had a magnitude of 5.1. Earthquakes of this size can cause significant damage depending on depth, location, and local building standards.
Saint Pierre and Miquelon has had 12 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.
Saint Pierre and Miquelon is classified in the "Low" seismic zone, located in North America. 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.