1957 Andreanof Islands earthquake

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1957 Andreanof Islands earthquake
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Anchorage
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UTC  time1957-03-09 14:22:33
ISC  event 886030
USGS-ANSS ComCat
Local dateMarch 9, 1957 (1957-03-09)
Local time04:22:33
Magnitude8.6–9.1 Mw [1] [2]
8.1–8.3 Ms [3] [2]
9.0 Mt [4] [lower-alpha 1]
Depth25 km (16 mi) [1]
Epicenter 51°30′N175°38′W / 51.5°N 175.63°W / 51.5; -175.63 [1]
Fault Aleutian Trench
Type Megathrust
Areas affected Aleutian Islands & Hawaii
Total damage $5 million [6]
Max. intensity VIII (Severe) [6]
Tsunami23 m (75 ft) [7]
Casualties2 dead (indirect)

The 1957 Andreanof Islands earthquake occurred at 04:22 local time on March 9 with a moment magnitude estimated between 8.6 and 9.1 and a maximum Modified Mercalli intensity of VIII (Severe). It occurred south of the Andreanof Islands group, which is part of the Aleutian Islands arc. The event occurred along the Aleutian Trench, the convergent plate boundary that separates the Pacific Plate and the North American plates near Alaska. A basin-wide tsunami followed, with effects felt in Alaska and Hawaii, and strong waves recorded across the Pacific rim. Total losses were around $5 million (equivalent to $52,097,156in 2022).

Contents

Tectonic setting

Map showing the tectonics and seismicity of Alaska Alaska earthquakes.jpg
Map showing the tectonics and seismicity of Alaska

The Aleutian Islands lie between Kamchatka and mainland Alaska. They were formed as the result of the 4,000 km (2,500 mi) long convergent boundary that accommodates the subduction of the oceanic Pacific Plate underneath the continental North American Plate. [8] This oceanic trench runs from the Kuril-Kamchatka Trench in the west to the Yakutat Collision Zone in the east. Most of the trench ruptured in a sequence of earthquakes from east to west. [5] Earthquakes in 1938, 1946, 1948, and 1965 generally progressed westward with smaller earthquakes filling in any gaps. [5] At each terminus of the subduction zone, convergence ends in favor of right-lateral transform faults. [9] In the west, convergence becomes increasingly oblique until the Commander Islands where faulting is nearly completely strike-slip—a 2017 earthquake was associated with this tectonic setting. [10] The plate boundary ends at the Kuril-Kamchatka Trench. [9] In the east, the Pacific Plate continues to subduct underneath the North American plate until the Yakutat microplate. [11] There, a transition from subduction to strike-slip faulting exists. [11] When this transition ends, faulting is completely right-lateral transform and is largely accommodated along the Queen Charlotte Fault. [11]

Earthquake

The seismic intensity peaked at VIII (Severe) on the Modified Mercalli intensity scale at Adak and Umnak. [3] As the shock occurred before the World Wide Standardised Seismological Network was in operation, few instruments recorded the event, and its mechanism is not understood well as a result. Some effort was made with the limited data to gain an understanding of the rupture area and the distribution of slip. One aspect of the event that was certain was that the 1,200–1,230 km (750–760 mi) aftershock zone was the largest that had ever been observed. [12] [13] The aftershock zone may slightly overlap other ruptures, however there is minimal overlap between the aftershocks of the 1946 Aleutian Islands earthquake to the east and the 1965 Rat Islands earthquake to the west. [13] Studies[ specify ] of the event differ on rupture characteristics. Some suggest a rupture zone greater than 600 km (370 mi), stretching from Amchitka Pass in the east to Unimak Pass in the west. [14] Other studies[ specify ] have the rupture area at a significantly longer 850 km (530 mi). [12] Yet other studies[ specify ] conclude that the entirety of the aftershock area ruptured in the earthquake, for a total rupture length of 1,200 km (750 mi). [15] The western portion of the rupture stopped at Bowers Ridge. [16] Studies also disagree on whether the easternmost area near Unalaska ruptured. Some of the early scientific papers[ specify ] conclude that this area remained unruptured during the event and remains a seismic gap. [12] Others, especially ones written decades after the fact, conclude that slip did occur here, [17] but signals from it were blocked by the coda of the main slip. [12] However, the amount of slip is not agreed upon. Some studies support a low amount of slip, [18] while others conclude that there was large amounts of slip in this area, [19] up to 20 m (66 ft). [20] A maximum slip of 20 m (66 ft) was estimated in the eastern portion of the rupture. [20] If the eastern portion of the megathrust did rupture, then a magnitude of Mw 9.0-9.1 is more reflective of the event. [17] The tsunami created by the earthquake suggests a (Mt 9.0) event. [4]

Tsunami

Teletsunami observations [14] [7]
LocationRecorded height (m)
Hāʻena, Kauai County, Hawaii, Hawaii16.1
Wainiha, Hawaii, Hawaii11.6
Pololu Valley, Hawaii9.8
Oahu, Hawaii7.0
Fagasā, American Samoa 1.5
Crescent City, California 0.7
San Diego, California0.2

Tsunami waves were reported in far way places such as in Chile. [21] The tsunami's strength led to suspicion that a landslide may have contributed to its severity, but there is no evidence of a landslide. [19] A submarine landslide is considered inconsistent with the wave patterns recorded, and the high wave heights could be explained by large amounts of near trench slip. [19]

Alaska

Wave heights were the highest in Alaska. On Unimak Island, waves reached as high as 23 m (75 ft). [7] Also on Unimak, near the Scotch Cap Lighthouse that was destroyed in the 1946 earthquake, run up heights of 12–15 m (39–49 ft) were observed. [14] Trappers Cove recorded wave heights of 13.7 m (45 ft). [22] At Sand Bay, the tsunami reached 8 m (26 ft). [14] Dutch Harbor in Unalaska recorded waves of 0.7 m (2 ft 4 in), Massacre Bay in Attu recorded waves up to 0.6 m (2 ft 0 in) high and Sitka had waves reaching 0.4 m (1 ft 4 in). [14] At Yakutat run-ups measured 0.3 m (1 ft 0 in), while Women's Bay, Kodiak, Seward, and Juneau had recorded tsunami heights of 0.2 m (7.9 in). [14]

Hawaii

On the island of Kauai, the wave height reached 16.1 metres (53 ft) at Haena. [14] In northern Oahu, wave heights reached 7 m (23 ft). [14] Various areas around Big Island recorded tsunami waves with heights ranging 1–9.8 m (3 ft 3 in – 32 ft 2 in), [14] including a reading of 3.9 m (13 ft) at Hilo. [23] In Kahului, Maui, tide gauges recorded waves up to 1.8 m (5 ft 11 in). [14] Coconut Island was submerged by 1 m (3 ft 3 in). [14]

California

Crescent City recorded a tsunami wave of 0.7 m (2 ft 4 in). [14] Los Angeles recorded run-ups of 0.5 m (1 ft 8 in), Santa Monica experienced a 0.5 m (1 ft 8 in)-high tsunami, while Anaheim Bay had 0.4 m (1 ft 4 in) waves. [14] San Francisco's tide gauge recorded run-ups of 0.3 m (1 ft 0 in). [14] In San Diego, a 1 m (3 ft 3 in) wave caused minor damage, however the tide gauge only recorded a wave 0.2 m (7.9 in) high. [14] Other tide gauges across the state recorded run-up heights of 0.1–0.5 m (3.9 in – 1 ft 7.7 in). [14]

Elsewhere

At Fagasā, American Samoa, tsunami run-up heights reached 1.5 m (4 ft 11 in). [14] Pago Pago recorded wave heights of 0.3 m (1 ft 0 in), however the amplitude of the wave was 1.2 m (3 ft 11 in). [14] Midway recorded tsunami waves up to 0.5 m (1 ft 8 in) high. [14] Wake Island recorded amplitudes of 0.4 m (1 ft 4 in), Kwajalein and Enewetak recorded heights of 0.3 m (1 ft 0 in). [14] Johnston Atoll experienced waves of 0.1 m (3.9 in), while waves less than 0.1 m (3.9 in) were recorded at Guam and Chuuk Lagoon. [14] In Mexico, the tidal gauge in Ensenada, Baja California recorded the strongest waves at 1.0 m (3.4 ft). [21] Many countries in Central America also recorded tsunami run-ups including 0.24 m (0.8 ft) at Puntarenas, Costa Rica, 0.18 m (0.6 ft) at Puerto San José, Guatemala, and 0.061 m (0.2 ft) waves at La Unión, El Salvador. [21] Peru and Chile were favorably oriented for large waves from the tsunami, and as a result strong waves were recorded. In Peru, the strongest wave heights of 1.3 m (4.2 ft) were recorded at Matarani, with other coastal areas recording wave heights of 0.27–0.79 m (0.9–2.6 ft). [21] Valparaiso, Chile recorded wave heights of 2.0 m (6.7 ft), which were the highest across the country. [21] Across the rest of the country, wave heights of 0.91 m (3.0 ft), 0.91 m (3.0 ft), 1.3 m (4.2 ft), and 1.4 m (4.6 ft) were recorded at Arica, Antofagasta, Caldera, and Talcahuano, respectively. [21]

Damage

Prompt warnings from the Seismic Sea Wave Warning System were credited with preventing major damage or loss of life. [14] The earthquake caused severe damage to roads and buildings on Adak including a crack 4.5 m (15 ft) in size, [6] however there were no deaths. [14] Two bridges and some oil and fuel-related structures at a dock were also destroyed there. [14] On Umnak, a concrete mixer and some docks were lost. [14] At Chernofski, [24] Trappers Cove, and Vsevidof, strong waves drowned sheep. [22] Oil pipelines were damaged at Sand Bay. [22] Many boats were damaged from strong waves. [22]

The tsunami caused twice the damage the tsunami of the 1946 earthquake did. [14] In Hawaii, damage was much more extensive, including two indirect fatalities that occurred when a pilot and photographer were killed while attempting to document the tsunami's arrival from an airplane. About 50 homes were flooded on the north shore of Oahu and significant effects were seen in Waialua Bay. Buildings and bridges were also flooded in Haleiwa. [14] In Hilo, the tsunami damaged buildings. [23] The total damage cost was over $5 million ($46 million in 2017). [7]

See also

Notes

  1. ↑ Other estimates include mb 7.7, [3] Ms20 8.2, [5] and M8.3. [3]

Related Research Articles

Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (Mw) that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes.

<span class="mw-page-title-main">1946 Aleutian Islands earthquake</span> Earthquake near the Aleutian Islands, Alaska

The 1946 Aleutian Islands earthquake occurred near the Aleutian Islands, Alaska on April 1, 1946. The shock measured 8.6, Mt 9.3 or 7.4. It had a maximum Mercalli intensity of VI (Strong). It resulted in 165–173 casualties and over US $26 million in damage. The seafloor along the fault was elevated, triggering a Pacific-wide tsunami with multiple destructive waves at heights ranging from 45–138 ft (14–42 m). The tsunami obliterated the Scotch Cap Lighthouse on Unimak Island, Alaska among others, and killed all five lighthouse keepers. Despite the destruction to the Aleutian Island Unimak, the tsunami had almost an imperceptible effect on the Alaskan mainland.

<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">Aleutian Trench</span> An oceanic trench along the southern coastline of Alaska and the Aleutian islands

The Aleutian Trench is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands. The trench extends for 3,400 kilometres (2,100 mi) from a triple junction in the west with the Ulakhan Fault and the northern end of the Kuril–Kamchatka Trench, to a junction with the northern end of the Queen Charlotte Fault system in the east. It is classified as a "marginal trench" in the east as it runs along the margin of the continent. The subduction along the trench gives rise to the Aleutian Arc, a volcanic island arc, where it runs through the open sea west of the Alaska Peninsula. As a convergent plate boundary, the trench forms part of the boundary between two tectonic plates. Here, the Pacific Plate is being subducted under the North American Plate at a dip angle of nearly 45°. The rate of closure is 7.5 centimetres (3 in) per year.

<span class="mw-page-title-main">2006 Pangandaran earthquake and tsunami</span> Destructive tsunami earthquake south of Java Island

An earthquake occurred on July 17, 2006 at 15:19:27 local time along a subduction zone off the coast of west and central Java, a large and densely populated island in the Indonesian archipelago. The shock had a moment magnitude of 7.7 and a maximum perceived intensity of IV (Light) in Jakarta, the capital and largest city of Indonesia. There were no direct effects of the earthquake's shaking due to its low intensity, and the large loss of life from the event was due to the resulting tsunami, which inundated a 300 km (190 mi) portion of the Java coast that had been unaffected by the earlier 2004 Indian Ocean earthquake and tsunami that was off the coast of Sumatra. The July 2006 earthquake was also centered in the Indian Ocean, 180 kilometers (110 mi) from the coast of Java, and had a duration of more than three minutes.

The 1995 Antofagasta earthquake occurred on July 30 at 05:11 UTC with a moment magnitude of 8.0 and a maximum Mercalli intensity of VII. The Antofagasta Region in Chile was affected by a moderate tsunami, with three people killed, 58 or 59 injured, and around 600 homeless. Total damage from the earthquake and tsunami amounted to $1.791 million.

<span class="mw-page-title-main">1861 Sumatra earthquake</span> Natural disaster in Indonesia

The 1861 Sumatra earthquake occurred on 16 February and was the last in a sequences of earthquakes that ruptured adjacent parts of the Sumatran segment of the Sunda megathrust. It caused a devastating tsunami which led to several thousand fatalities. The earthquake was felt as far away as the Malay peninsula and the eastern part of Java. The rupture area for the 2005 Nias–Simeulue earthquake is similar to that estimated for the 1861 event.

The 1965 Rat Islands earthquake occurred at 05:01 UTC, on 4 February. It had a magnitude of 8.7 and triggered a tsunami of over 10 m on Shemya Island, but caused very little damage.

<span class="mw-page-title-main">Tsunami earthquake</span> Type of earthquake which triggers a tsunami of far-larger magnitude

In seismology, a tsunami earthquake is an earthquake which triggers a tsunami of significantly greater magnitude, as measured by shorter-period seismic waves. The term was introduced by Japanese seismologist Hiroo Kanamori in 1972. Such events are a result of relatively slow rupture velocities. They are particularly dangerous as a large tsunami may arrive at a coastline with little or no warning.

The 1959 Kamchatka earthquake occurred on May 4 at 19:15 local time with a moment magnitude of 8.0–8.3, and a surface wave magnitude of 8.25. The epicenter was near the Kamchatka Peninsula, Russian SFSR, USSR. Building damage was reported in Petropavlovsk-Kamchatsky. The maximum intensity was VIII (Damaging) on the Medvedev–Sponheuer–Karnik scale. The intensity in Petropavlovsk-Kamchatsky was about VIII MSK.

The 1907 Sumatra earthquake occurred on January 4 at 05:19:12 UTC. The estimated magnitude is 7.5–8.0 Ms, with an epicentre close to Simeulue, off Sumatra. It triggered a widespread and damaging tsunami that caused at least 2,188 deaths. The low observed intensity compared to the size of the tsunami has led to its interpretation as a tsunami earthquake. Higher levels of shaking observed on Nias are attributed to a large aftershock, less than an hour later. The tsunami gave rise to the S'mong legend, which is credited with saving many lives during the 2004 earthquake.

On July 17 2017, 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 large supershear earthquake has been observed. It was preceded by a few foreshocks months earlier, and aftershocks that continued for nearly six months.

The Nemuro-Oki earthquake in scientific literature, occurred on June 17 at 12:55 local time. It struck with an epicenter just off the Nemuro Peninsula in northern Hokkaidō, Japan. It measured 7.8–7.9 on the moment magnitude scale (Mw ), 8.1 on the tsunami magnitude scale (Mt ) and 7.4 on the Japan Meteorological Agency magnitude scale (MJMA ).

<span class="mw-page-title-main">1585 Aleutian Islands earthquake</span> 16th-century seismic event in the North Pacific Ocean

The 1585 Aleutian Islands earthquake is the presumed source of a tsunami along the Sanriku coast of Japan on 11 June 1585, known only from vague historical accounts and oral traditions. The event was initially misdated to 1586, which led to it being associated with the deadly earthquakes in Peru and Japan of that year. A megathrust earthquake on the Aleutian subduction zone in the North Pacific Ocean was hypothesized as the tsunami's source. Paleotsunami evidence from shoreline deposits and coral rocks in Hawaii suggest that the 1585 event was a large megathrust earthquake with a moment magnitude (Mw ) as large as 9.25.

<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 on February 11, 2021 at 00:19 local time. 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 the South Atlantic region, and is tied with the 2021 Kermadec Islands earthquake as the second largest earthquake of 2021.

The 1979 Yapen earthquake occurred on September 12 at 05:17:51 UTC. It had an epicenter near the coast of Yapen Island in Irian Jaya, Indonesia. Measuring 7.5 on the moment magnitude scale and having a depth of 20 km (12 mi), it caused severe damage on the island. At least 115 were killed due to shaking and a moderate tsunami.

The 1979 Saint Elias earthquake occurred near noon local time on 28 February. It measured Mw 7.4–7.6. Though the maximum recorded Modified Mercalli intensity was VII, damage was minimal and there were no casualties due to the remoteness of the faulting. The epicenter lies near the Alaskan border between the United States and Canada.

<span class="mw-page-title-main">1940 Shakotan earthquake</span> Earthquake in Japan

The 1940 Shakotan earthquake occurred on August 2 at 00:08:22 JST with a moment magnitude (Mw ) of 7.5 and maximum JMA seismic intensity of Shindo 4. The shock had an epicenter off the coast of Hokkaido, Japan. Damage from the shock was comparatively light, but the accomanying tsunami was destructive. The tsunami caused 10 deaths and 24 injuries on Hokkaido, and destroyed homes and boats across the Sea of Japan. The highest tsunami waves were recorded at the coast of Russia while along the coast of Hokkaido, waves were about 2 m.

References

  1. 1 2 3 International Seismological Centre. On-line Bulletin. Thatcham, United Kingdom.[Event  886030 ].
  2. 1 2 Kanamori 1977.
  3. 1 2 3 4 Brockman, Espinosa & Michael 1988.
  4. 1 2 Abe 1979.
  5. 1 2 3 Sykes 1971.
  6. 1 2 3 Stover & Coffman 1993.
  7. 1 2 3 4 "Tsunami Historical Series: Aleutian Islands - 1957 Dataset | Science On a Sphere". sos.noaa.gov. 28 March 2017. Retrieved 24 January 2020.
  8. ↑ "Aleutian Trench". Archived from the original on February 25, 2014. Retrieved August 7, 2022.
  9. 1 2 Yeats 2012.
  10. ↑ Lay et al. 2017.
  11. 1 2 3 Doser 2012.
  12. 1 2 3 4 Johnson et al. 1994.
  13. 1 2 Tape & Lomax 2022.
  14. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Lander & Lockridge 1989.
  15. ↑ Hwang & Kanamori 1986.
  16. ↑ Davies et al. 1981.
  17. 1 2 Witter et al. 2019.
  18. ↑ Boyd & Jacob 1986.
  19. 1 2 3 Witter et al. 2016.
  20. 1 2 Nicolsky et al. 2016.
  21. 1 2 3 4 5 6 Salsman 1959.
  22. 1 2 3 4 Lander 1996.
  23. 1 2 "1957 Aleutian Tsunami". Earthweb. University of Washington. Retrieved 29 December 2022.
  24. ↑ "The 9 March 1957 Aleutian Tsunami" (PDF). Intergovernmental Oceanographic Commission United Nations Educational, Scientific and Cultural Organization. Retrieved 30 December 2022.

Sources

Abe, Katsuyuki (1979). "Size of great earthquakes of 1837–1974 inferred from tsunami data". Journal of Geophysical Research. 84 (B4): 1561–1568. Bibcode:1979JGR....84.1561A. doi:10.1029/JB084iB04p01561 . Retrieved 31 December 2022.

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