Earthquake Review: September 2022

Published: 10/05/2022

Summary of damaging earthquakes in September 2022: Multiple large and deadly quakes across the globe.

General summary:

After August 2022 became one of the seismically calmest months with one of the lowest damage statistics on record, September turned the tide. 123 casualties, 931 injuries and more than 75000 damaged buildings from 28 damaging events, seven of them deadly, marks the most destructive month of the year behind June (when one earthquake in Afghanistan alone contributed to most losses). These quakes affected 20 countries of which Liechtenstein, Switzerland and Paraguay had their first damaging earthquake in years.

Damaging earthquakes:

The seventh deadly earthquake of the year in Afghanistan: A shallow 5.3 hit the western Region of Jalalabad near the border to Pakistan on September 4th. An unknown number of houses was destroyed by the quake. Several small landslides were triggered. At least nine people died due to the earthquake effects, 42 others were injured and 2000 residents displaced.

The most destructive and deadly China earthquake for one year. As most of the previous destructive quakes in China, the province of Sichuan was hit again. The Magnitude 6.6 quake affected the region southwest of the province capital Chengdu on September 5th, leading to severe landslides and damage to at least 50.000 buildings. Due to the landslides, hundreds of roads, power lines and other infrastructure were destroyed. In the latest official statement published in mid-September, 95 people were killed with more than 20 remaining missing.

A very strong, deep earthquake hit north-western Papua New Guinea on September 10th. With Magnitude 7.6 it was the strongest earthquake in this area in decades. Due to large magnitude and depth, widespread and destructive effects were reported from the rural and partially very remote areas. Many losses were caused by co-seismic landslides which destroyed several villages, food gardens and infrastructure. The exact extent of the destruction remains unknown. 12 casualties is the official death toll with up to 10.000 people possibly displaced, according to PNG Red Cross.

A sequence of strong earthquakes hit south-western Taiwan from September 17th to 20th. Following an initial M6.4, a Magnitude 6.9 earthquake hit the provinces Taitung and Hualien. Several buildings and bridges collapsed. At least one person died, 171 others were injured. Minor damage was reported from many parts of Taiwan, including the capital area around Taipeh. More than one thousand buildings were affected, of that 91 residential buildings in Taitung and Hualien that were declared uninhabitable.

Another pair of large earthquakes hit Mexico on September 19th and September 22nd. The initial M7.6 earthquake, the strongest in Mexico for five years, affected many parts of Michoacan, Colima and Jalisco state. The second quake with Magnitude 6.8 caused additional damage. The total preliminary death toll of these events stands at five with at least 37 other people injured. More than 14,000 damaged buildings were identified so far with 2222 declared unsafe or completely collapsed. The mainshock was followed by a tsunami that flooded some coastal roads in Manzanillo, Colima.

More than 2600 buildings were damaged or destroyed by a shallow M5.9 earthquake at the Great Sumatra Fault near Lake Toba on the Indonesian Island Sumatra. At least 352 houses were completely destroyed. One person died, 24 others were injured.

Tsunamis:

The tsunami following the earthquake in Mexico on September 19th reached a maximum amplitude of 79 cm, lead to minor floodings of roads near the coast but didn’t cause any significant damage. It was the largest earthquake-related tsunami so far in 2022. A smaller tsunami (9 cm) followed the M6.8 aftershock three days later.

Volcanic Eruption:

No damaging earthquakes associated with volcanic activity were recorded this month. However, at Lake Taupo in New Zealand a sequence of minor to moderate earthquake reached its preliminary peak this month with a Magnitude 4.2 events. By elevating the volcanic alert level, authorities warns that this period of unrest and enhanced seismicity might continue without expecting any volcanic activity in the near future.

A strong, still ongoing earthquake sequence at the northern Mid-Atlantic Ridge began in the last week of September. It’s strongest September quake occurred on the 30th and reached Magnitude 5.7 (followed by a 5.9 on October 1st). Geophysical analysis of seismic waves found indicators for an ongoing magmatic intrusion, maybe a large submarine eruption along the ridge zone at approx. 53.7°N. However, this place is located more than 1300 km away from the closest coasts of Canada and Ireland so that neither the earthquakes nor a possible volcanic eruption pose any threat to human settlements.

Landslides:

In the Skardu District of Northern Pakistan several moderate to strong earthquakes have caused damage and landslides over the past months. The latest event on September 19th (M4.3) lead to massive rockfalls on roads and villages. At least eight people were injured in these incidents and some houses damaged.

Two houses were damaged by a small landslide that followed a shallow 3.8 earthquake in the Chinese province Guangxi on September 28th. Four people were evacuated from these houses. Additionally, rockfall affected 28 roads. The earthquake itself damaged additional 47 buildings.

Other co-seismic landslides or rockfalls affected Western Greece and the Iranian province Hormozgan on September 8th and September 5th, respectively. While the rockfalls from both M5.4 earthquakes remained harmless, the Iran quake additionally damaged some houses.

Induced earthquakes:

In the Dutch province of Groningen a magnitude 2.7 earthquake occurred on September 24th. 179 damage claims that could be related to this earthquake and a minor aftershock were received by NAM, the operator of the Groningen gas field that is known for induced seismicity.

Other earthquakes:

With three earthquakes with Magnitude 7 or larger, September 2022 was clearly above long-term seismicity average. Except the previously discussed quakes in Mexico and Papua New Guinea, a magnitude 7.0 happened south of Vanuatu on September 14th without causing any damage. A total of 17 earthquake of Magnitude 6 or larger is also above long-term average.

Recent Reports

Two destructive earthquakes caused 99% of all October losses.

Summary of damaging earthquakes in September 2022: Multiple large and deadly quakes across the globe.

Summary of damaging earthquakes in August 2022: Very low seismicity and losses.

Multiple earthquake sequences, destructive events and volcanic effects led to more than 30,000 damaged buildings.

A deadly combination of earthquake properties and regional characteristics resulted in one of the worst disasters in Afghan history