In the early afternoon of Monday November 20th, 2023, a shallow M4.9 earthquake hit in the Tasman Sea 296 kilometer from Invercargill, New Zealand.
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Earthquake Summary
This earthquake hit under water in the Tasman Sea, 259 kilometers (161 mi) off the coast of New Zealand, 296 kilometer southwest of Invercargill in Southland. The center of this earthquake had a very shallow depth of 10 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.
| Date and Time: | Nov 20, 2023 13:36 (Auckland Time) - Nov 20, 2023 00:36 Universal Time. |
|---|---|
| Location: | 296 km SW of Invercargill, Southland, New Zealand. Coordinates 48°6'23"S 165°20'52"E. |
| Map: |  Map of area around epicenter. Click to open in Google Maps. |
| Magnitude: | MAG 4.9 Detected by 22 stations. Maximum Error Range ±0.119 . |
| Depth: | 10 km (6 mi) A very shallow depth. |
| Tsunami Risk: | Low tsunami risk Earthquakes under MAG-6.5 do not usually cause tsunami's. Always stay cautious - More info here. |
Nearby towns and cities
This earthquake may have been felt in New Zealand . The closest significant population center near the earthquake is Invercargill in Southland, New Zealand. Invercargill is located 296 kilometer (184 mi) southwest of the epicenter.
Overview of nearby places
| Distance | Place |
|---|---|
| 296 km (184 mi) NE from epicenter |
Invercargill Southland, New Zealand. |
Risk of aftershocks?
This earthquake did not have any significant foreshocks nor aftershocks occurring within 100km (62 mi) of its epicenter.
Aftershocks are usually at least 1 order of magnitude less strong than main shocks. The more time passes, the smaller the chance and likely strength of any potential aftershocks.
The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk
Read: How to Stay Safe during an Earthquake (cdc.gov).Earthquakes like this happen often in the region
Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since May 31st, 2023, when a 6.3 magnitude earthquake hit 200 km (124 mi) further south-southwest. An even stronger magnitude 6.6 earthquake struck on July 11th, 2017.
In total, 25 earthquakes with a magnitude of 4.9 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every 5 months.
Low tsunami risk
Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so stay cautious and monitor advice from local authorities.
Tsunami Risk Factors
| Factor | Under Sea? | MAG-6.5 or stronger? | Shallow depth? |
|---|---|---|---|
| Explanation | Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami. | Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's. |
Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor. |
| This Earthquake | This earthquake appears to have struck under the sea. | Not this earthquake. This earthquake had a magnitude of 4.9. Earthquakes of this strength are unlikely to trigger a tsunami. |
This earthquake occurred at a depth of of 10 km (6 mi). Earthquakes this shallow could trigger a tsunami. |
Sources
Last updated 30/11/23 00:58 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.
- US Geographic Society (USGS): Earthquake us6000lpit
- European-Mediterranean Seismological Centre (EMSC): Earthquake 20231120_0000003
- Geonames.org: World Cities Database
- Google Maps: Static API
- Earthquakelist.org: Historic Earthquakes Database
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