2009 Vanuatu earthquakes

Last updated
2009 Vanuatu earthquakes
Oceania laea relief location map.jpg
Bullseye1.png
UTC  time2009-10-07 22:03:14
 2009-10-07 22:18:51
 2009-10-07 23:13:48
USGS-ANSS ComCat
  ComCat
  ComCat
Local dateOctober 8, 2009 (2009-10-08)
Local time09:03
 09:18
 10:13
Magnitude7.7 Mw
 7.8 Mw
 7.4 Mw
Depth45.0 km (28 mi)
 35.0 km (22 mi)
 31.1 km (19.3 mi)
Epicenter 12°31′01″S166°22′55″E / 12.517°S 166.382°E / -12.517; 166.382 Coordinates: 12°31′01″S166°22′55″E / 12.517°S 166.382°E / -12.517; 166.382
Max. intensity IX (Violent) [1]
Tsunami62 cm (2.03 ft) [2]
AftershocksYes, strongest being Mw 7.4 [3]
CasualtiesNone

The 2009 Vanuatu earthquakes were three earthquakes with magnitudes ranging from 7.4 to 7.8, constituting some of the largest earthquakes in Vanuatu's history.

Contents

Tectonic Setting

The Vanuatu earthquakes of October 7, 2009: M 7.7, Vanuatu, 22:03:14; M 7.8 Santa Cruz Islands, 22:18:51 UTC; and M 7.4, Vanuatu, 23:13:48; all occurred as a result of shallow reverse faulting on or near the plate boundary interface between the Indo-Australian Plate and Pacific Plates. In the region of these earthquakes, the Indo-Australian plate moves to the east-northeast with respect to the Pacific plate at a velocity of about 91 mm/yr. The Indo-Australian plate thrusts under the Pacific plate at the New Hebrides Trench and dips to the east-northeast. The locations, depths, and focal mechanism solutions for the October 7th events are all consistent with them resulting from reverse faulting associated with subduction along the Australia-Pacific plate boundary.

The 7.8 Mw earthquake of October 7, 2009 (22:18 UTC), occurred about 60 km north, and 15 minutes after, a slightly smaller earthquake with a 7.7 Mw of the same date Occurred (22:03 UTC). A third, smaller event at 7.4 Mw occurred at 23:13 UTC, 15 km to the southeast of the first event. All three events are likely related; while the first two similarly sized events may be considered a doublet earthquake, preliminary analysis suggests that the 7.4 Mw earthquake is likely a large aftershock of one of the events. [3]

Earthquake

More than a dozen earthquakes above 5.0 magnitude shook the country within two days of the earthquake sequence, [4] The largest earthquake of the sequence, measuring a magnitude of 7.8, Mw struck the province of Torba, with an epicentre 294 km (183 mi) northwest of the island of Espiritu Santo, [5] and is the second largest earthquake of 2009. None of these tremors caused any casualties. [6]

Aftershocks and other events

About 15 minutes prior, a magnitude 7.7 earthquake struck the same area. Due to them occurring in the same region, both events are considered a doublet earthquake. [1] About an hour after that event, a magnitude 7.4 earthquake struck the same area, it is considered an aftershock to one of the events. [3] At least nine aftershocks of magnitude six or higher were recorded by the USGS. [7] Some of the aftershocks, as large as magnitude 6.1, were located in the Solomon Islands. [8] the largest earthquakes of the aftershock sequence were the aforementioned 7.4 event as well as a magnitude 6.8 tremor on October 8. [9] On June 3, 2009, an unrelated magnitude 6.3 earthquake struck 38 km west of the capital of Port-Vila, injuring four, damaging a few buildings and triggering landslides. [10]

Tsunami

A tsunami was observed all over the Pacific Ocean, with waves as high as 62 cm (2.03 ft) in Port-Vila, Vanuatu, 30 cm (0.98 ft) in Santa Monica, California, and 16 cm (0.52 ft) in Atka, Alaska. [2]

See also

Related Research Articles

<span class="mw-page-title-main">Kamchatka earthquakes</span> Earthquakes in the Kamchatka Peninsula, far eastern Russia

Many major earthquakes have occurred in the region of the Kamchatka Peninsula in far eastern Russia. Events in 1737, 1923 and 1952, were megathrust earthquakes and caused tsunamis. There are many more earthquakes and tsunamis originating from the region.

<span class="mw-page-title-main">September 2007 Sumatra earthquakes</span> Earthquakes affecting Indonesia

The September 2007 Sumatra earthquakes were a series of megathrust earthquakes that struck the Sunda Trench off the coast of Sumatra, Indonesia, with three of magnitude 7 or greater. A series of tsunami bulletins was issued for the area. The most powerful of the series had a magnitude of 8.5, which makes it in the top 20 of the largest earthquakes ever recorded on a seismograph.

The 2000 New Ireland earthquakes occurred off the coast of New Ireland Province, Papua New Guinea on November 16 and 17.

<span class="mw-page-title-main">April 2011 Miyagi earthquake</span>

The April 2011 Miyagi earthquake occurred off the coast of Miyagi Prefecture, approximately 66 kilometres (41 mi) east of Sendai, Japan. The Mw7.1 thrust earthquake was classified as an aftershock of the March 11 Tōhoku earthquake, and occurred at 23:32 JST (14:32 UTC) on Thursday, 7 April 2011.

<span class="mw-page-title-main">June 2011 Christchurch earthquake</span> June 2011 earthquake in New Zealand

The June 2011 Christchurch earthquake was a shallow magnitude 6.0 Mw earthquake that occurred on 13 June 2011 at 14:20 NZST. It was centred at a depth of 7 km (4.3 mi), about 5 km (3 mi) south-east of Christchurch, which had previously been devastated by a magnitude 6.2 MW earthquake in February 2011. The June quake was preceded by a magnitude 5.9 ML tremor that struck the region at a slightly deeper 8.9 km (5.5 mi). The United States Geological Survey reported a magnitude of 6.0 Mw and a depth of 9 km (5.6 mi).

The 1971 Solomon Islands earthquakes occurred in the northern part of the Solomon Islands, within Papua New Guinea as a doublet earthquake. The first large shock occurred on July 14 at 06:11 UTC with a magnitude of Mw 8.0. The second large event occurred on July 26 at 01:23 UTC with a magnitude of Mw  8.1. The initial event on July 14 caused a tsunami, which was observed in Rabaul. The earthquake of July 26 triggered a tsunami with a 3.4 m (11 ft) runup in New Britain.

The 2012 Indian Ocean earthquakes were magnitude 8.6 and 8.2 Mw  undersea earthquakes that struck near the Indonesian province of Aceh on 11 April at 15:38 local time. Initially, authorities feared that the initial earthquake would cause a tsunami and warnings were issued across the Indian Ocean; however, these warnings were subsequently cancelled. These were unusually strong intraplate earthquakes and the largest strike-slip earthquake ever recorded.

The 2012 Haida Gwaii earthquake occurred just after 8:04 p.m. PDT on October 27. The shock had a moment magnitude of 7.8 and a maximum Mercalli Intensity of V (Moderate). The earthquake's epicentre was on Moresby Island of the Haida Gwaii archipelago. This was the second largest Canadian earthquake ever recorded by a seismometer, after the 1949 Queen Charlotte Islands earthquake, about 135 kilometres (84 mi) away. One person died due to a car crash related to the tsunami in Oahu, Hawaii.

<span class="mw-page-title-main">2013 Solomon Islands earthquake</span> Megathrust earthquake and tsunami in Solomon Islands

The 2013 Solomon Islands earthquake struck Temotu Province within Solomon Islands on 6 February with a moment magnitude of 8.0 and a maximum Mercalli intensity of VIII (Severe). The epicentre was close to the Santa Cruz Islands within Temotu Province at the boundaries of the Indo-Australian and Pacific tectonic plates, causing local evacuations, a tsunami of 11 m (36 ft) and killing at least nine people.

<span class="mw-page-title-main">2013 Bushehr earthquake</span> 6.3 magnitude earthquake in Iran

The 2013 Bushehr earthquake occurred with a moment magnitude of 6.3 on April 9 in Iran. The shock's epicenter was in the province of Bushehr, near the city of Khvormuj and the towns of Kaki and Shonbeh. At least 37 people were killed, mostly from the town of Shonbeh and villages of Shonbeh-Tasuj district, and an estimated 850 people were injured.

The 2013 Balochistan earthquakes took place in late September in southwestern Pakistan. The mainshock had a moment magnitude of 7.7 and a maximum Mercalli intensity of IX (Violent). At least 825 people were killed and hundreds more were injured. On 28 September, a M6.8 aftershock occurred to the north at a depth of 14.8 kilometres, killing at least 22 people.

The 2014 Iquique earthquake struck off the coast of Chile on 1 April, with a moment magnitude of 8.2, at 20:46 local time. The epicenter of the earthquake was approximately 95 kilometres (59 mi) northwest of Iquique. The mainshock was preceded by a number of moderate to large shocks and was followed by a large number of moderate to very large aftershocks, including a M7.7 event on 3 April. The megathrust earthquake triggered a tsunami of up to 2.11 metres (6.9 ft) that hit Iquique at 21:05 local time. Similar-sized tsunamis were also reported to have hit the coasts of Pisagua and Arica.

<span class="mw-page-title-main">2016 Solomon Islands earthquakes</span> Seismic events

On 9 December 2016 at 4:38 a.m. local time, the Solomon Islands region was rocked by an Mww 7.8 earthquake, centered 30 km off San Cristobal Island, about 61 km southwest of Kirakira, the capital of Makira-Ulawa Province. Initially registering magnitude 8.0, later downgraded to 7.8, the temblor prompted tsunami warnings that kept countries surrounding the Coral, Tasman and Solomon Sea on high alert, but was later cancelled. A large aftershock of magnitude 6.9 occurred shortly afterwards. This earthquake was largely felt, waking many residents who later ran to high ground for fears of a potential tsunami. The earthquake killed a child and affected some 34,000 people in Makira, South Malaita and Guadalcanal Island where many had lost their homes or had no access to basic needs. Earthquakes are common in this region, with little or no fatalities. This earthquake is tied with three other magnitude 7.8 earthquakes for the second largest earthquake of 2016. On 17 December, the Solomon Islands would be rattled again by a 7.9 magnitude earthquake, this time 54 km east of Taron, Papua New Guinea.

The 2018 Fiji earthquakes occurred on August 19, at 00:19:40 UTC and on September 6 15:49 UTC. The epicenters were located close to the Fijian island Lakeba, and around 270 km from the small town of Levuka on Ovalau. The first earthquake registered a magnitude of Mww  8.2, and is the largest earthquake of 2018. It had a focal depth of 600 km, making it the second largest earthquake ever recorded at a depth greater than 300 km; a tie with the 1994 Bolivia earthquake, and behind the 2013 Okhotsk Sea earthquake. The initial earthquake was caused by a normal fault below the South Pacific Ocean. An Mww  7.9 event struck the islands again on September 6 at a depth of 670 km; this earthquake was a mainshock of its own. Both earthquakes may be considered a doublet event.

On July 17, an earthquake struck near the Komandorski Islands, east of the Kamchatka Peninsula in the Bering Sea at. Although there were no casualties from this earthquake, it was notable for a rare characteristic known as supershear, and is one of the few times a supershear earthquake has been observed. It was preceded by a few foreshocks months earlier, and aftershocks that continued for nearly six months.

The 2021 Kermadec Islands earthquakes were a series of earthquakes with magnitudes of 8.1 and 7.4 that occurred at 19:28:31 UTC on 4 March 2021. The epicentres were located southeast of Raoul Island in the Kermadec Islands, part of the New Zealand outlying islands. The main magnitude 8.1 earthquake was preceded by a magnitude 7.4 foreshock and followed by a magnitude 6.1 aftershock. A separate, unrelated magnitude 7.3 earthquake occurred off the coast of the North Island of New Zealand, approximately 900 km to the south, several hours before the main quakes. As of January 2023, there have been nearly 3,000 aftershocks, with more than a dozen of them exceeding magnitude 6.

<span class="mw-page-title-main">2021 Chignik earthquake</span> 7th largest earthquake in the US

An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.

The 2021 Loyalty Islands earthquake was a 7.7 magnitude earthquake that struck offshore between Vanuatu and New Caledonia. It is the 4th largest earthquake of 2021.

The 2021 South Sandwich Islands earthquakes were a pair of powerful earthquakes, followed by many strong aftershocks which struck along the South Sandwich Trench in August 2021. The quakes measured 7.5 and 8.1 on the moment magnitude scale, according to the United States Geological Survey. The mainshock is tied with another event in 1929 as the largest earthquake ever recorded in this region and the Atlantic Ocean as a whole, and is tied with the 2021 Kermadec Islands earthquake as the second largest earthquake of 2021.

<span class="mw-page-title-main">2002 Port Vila earthquake</span>

The 2002 Port Vila earthquake occurred in the early dawn of January 3, 2002, 04:22 a.m. local time (UTC+11) northwest of Port Vila, the capital of Vanuatu. It had a magnitude of 7.2 Mw and a maximum intensity of X (Extreme) west of the island on the Modified Mercalli intensity scale. There are no exact estimates on the number of injured individuals, but the majority of accounts say there were "several" amounts of injured civilians. the event also caused a minor tsunami of about 0.4−0.8 m just 11 minutes after the quake.

References

  1. 1 2 "M 7.7, Vanuatu". 7 October 2009.
  2. 1 2 "M 7.8 - 196 km NW of Sola, Vanuatu". 7 October 2009.
  3. 1 2 3 "M 7.4 - 143 km NW of Sola, Vanuatu". 7 October 2009.
  4. "Dozens of Tremors Rock Vanuatu". Earthquake Observatory. 9 October 2009.
  5. "3 Earthquakes Strike Vanuatu, No Casualties Reported". CBS News . 7 October 2009.
  6. "7.8 Magnitude earthquake Rocks Vanuatu". 7 October 2009.
  7. "lists, maps and statistics - 2009". 31 December 2009.
  8. "M 6.1 - 59 km S of Lata, Solomon Islands". 10 October 2009.
  9. "M 6.8 - 188 km NW of Sola, Vanuatu". 8 October 2009.
  10. "M 6.3 - 38 km W of Port-Vila, Vanuatu". 3 June 2009.