A shallow and significant Magnitude 5.5 earthquake struck under land 167 kilometer from Port Moresby in Papua New Guinea in the late afternoon of Tuesday November 21st, 2023. Shaking may have been felt by a total of 1 million people.
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Earthquake Summary
The earthquake struck on land in Papua New Guinea, 167 kilometer (104 mi) east of Port Moresby in National Capital. 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 21, 2023 17:10 (Port Moresby Time) - Nov 21, 2023 07:10 Universal Time. |
|---|---|
| Location: | 167 km east of Port Moresby, National Capital, Papua New Guinea. Coordinates 9°33'52"S 148°40'25"E. |
| Map: |  Map of area around epicenter. Click to open in Google Maps. |
| Magnitude: | MAG 5.5 Detected by 34 stations. Maximum Error Range ±0.053 . |
| Depth: | 10 km (6 mi) A very shallow depth. |
| Max. Intensity: | VII
Very Strong On the Modified Mercalli Scale. |
| Tsunami Risk: | Tsunami very unlikely While this was a shallow earthquake, it appears to have occurred under land with a magnitude not strong enough to cause tsunami's. Always stay cautious - More info here. |
Minimal impact predicted
Based on scientific estimates by the US Geographic Survey (USGS), the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.
The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 99% likelyhood of between 0 and 1 million US Dollars in economic damage and impact.
Roughly 1 million people exposed to shaking
The USGS has published a report estimating the number of people exposed to this earthquake. Acoording to their analysis, roughly 1 million have been exposed to shaking at an MMI level of II or higher.
An estimated 4,700 people were exposed to level VII. At this level, very strong shaking and likely moderate damage can be expected. Intensity level III was experienced by the majority of people (around 680 thousand). In their region, weak shaking and probably no damage can be expected. All exposure to shaking was within the borders of Papua New Guinea .
| People | MMI Level | Shaking | Damage |
|---|---|---|---|
| 0 | I |
Not noticable | None |
| 158,300 | II |
Very weak | None |
| 680,800 | III |
Weak | Probably none |
| 110,700 | IV |
Light | Likely none |
| 7,670 | V |
Moderate | Very light |
| 6,260 | VI |
Strong | Light |
| 4,700 | VII |
Very Strong | Moderate |
| 0 | VIII |
Severe | Moderate to heavy |
| 0 | IX |
Violent | Heavy |
| 0 | X |
Extreme | Very heavy |
Nearby towns and cities
This earthquake may have been felt in Papua New Guinea . Located 101 kilometer (63 mi) south-southeast of the epicenter of this earthquake, Popondetta (Northern Province, Papua New Guinea) is the nearest significant population center. The intensity of shaking and damage in Popondetta is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).
Overview of nearby places
| Distance | Place | Intensity (MMI) |
|---|---|---|
| 101 km (63 mi) NNW from epicenter |
Popondetta Northern Province, Papua New Guinea. |
III
Weak |
| 167 km (104 mi) W from epicenter |
Port Moresby National Capital, Papua New Guinea. |
II
Weak |
Earthquake Intensity Map
The maximum intensity (MMI Scale) caused by this earthquake is VII. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.
Risk of aftershocks?
This earthquake did not have any significant foreshocks nor aftershocks occurring within 100km (62 mi) of its epicenter.
Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.
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 are common in the region
Earthquakes of this strength occur quite regularly in the region. This is the strongest earthquake to hit since June 23rd, 2022, when a 5.5 magnitude earthquake hit 128 km (79 mi) further east. An even stronger magnitude 7 earthquake struck on July 17th, 2020.
In total, 6 earthquakes with a magnitude of 5.5 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 2 years.
Tsunami very unlikely
While MAG-6.5+ earthquakes may cause tsunami's, it appears that the epicenter of this earthquake hit under land. In addition, the reported depth is deeper than 100km, making the risk of a tsunami even less likely. However always 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 | Not this earthquake. This earthquake appears to have struck on land far from any coast. |
Not this earthquake. This earthquake had a magnitude of 5.5. 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 07:08 (). 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 us6000lprf
- European-Mediterranean Seismological Centre (EMSC): Earthquake 20231121_0000046
- Geonames.org: World Cities Database
- Google Maps: Static API
- Earthquakelist.org: Historic Earthquakes Database
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