Paleotsunami

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A paleotsunami is a tsunami that occurs prior to written history where there are no documented observations. [1] Paleotsunamis are evidenced by modern technology and scientific research. One of the largest was a megatsunami resulting from the asteroid that wiped out the dinosaurs. [2]

Contents

Studying paleotsunamis is an emerging science to identify and interpret paleotsunami deposits. [3] There are several recorded paleotsunami records, but though some are known only by historical mentions, such as tsunamis resulting from the 1700 Cascadia earthquake which is known only from oral traditions among the Native Americans of the Pacific Northwest.

Historical occurrences

Chile

On the coast of Chile, boulders have been found that "suggest directionality from sea to land," and they "could not be transported by rolling." [4]

On the northern Chilean coast, probable evidence of a tsunami exist as one boulder on the sand high above the Pacific can be found, dwarfing every other rock in view in a conspicuous manner. Based on the effects of a tsunami that hit Japan, a tsunami 20 m (66 ft) probably hit the Chilean coast in AD 1420, which swept boulders inland as if they were pebbles. [5]

The 1420 Caldera earthquake generated tsunamis reaching Japan. [6]

In the sea off of the Atacama near Caldera, on April 11, 1819, there was a magnitude 8.5 earthquake. It lasted roughly 7 min and almost completely demolished the city of Copiapó. A tsunami with waves up to 4 metres (13 ft) high was registered. It had reached all coasts within a radius of 800 kilometres (500 mi), including Hawaii. [7]

Age determination of paleotsunami sediments around Lombok Island, Indonesia, and identification of their possible tsunamigenic earthquakes. Fig3-Stratigraphy-of-the-Gawah-Pudak-trench-South-Lombok.jpg
Age determination of paleotsunami sediments around Lombok Island, Indonesia, and identification of their possible tsunamigenic earthquakes.

New Zealand

In New Zealand, large boulders have been found close to 1 kilometre (0.62 mi) inland. No tsunami appears in historical records, but it is estimated to have occurred around 1777 BC. It likely hit islands all across the South Pacific, including the Cook Islands, Tonga, and Vanuatu. Paleotsunami researchers do not yet know the full scale of the destruction the tsunami caused. [5]

China

A tsunami struck in AD 1076 in southern China, during the Song dynasty and nearly wiped out civilization in what is now Guangdong. On Lincoln Island of the Paracel chain in the South China Sea, large rocks and coral have been deposited on the island far away from the coast which can be explained to be moved there due to the tsunami. The earthquake causing it was probably in the Manila Trench. Historical record show that earthquake activity was largely cut off and major activity did not resume for centuries. [8]

There is evidence of paleotsunami events occurring on Taiwan. [9] [10]

The Cascadia Subduction Zone

Off the coast of the American Northwest, the 1700 Cascadia earthquake generated a tsunami. It was recorded in Japan. [11] The Indigenous peoples of the Pacific Northwest Coast carried the story on in many oral traditions, [12] though they left no written records. There are records of several paleotsunamis hitting the southwest coast of Canada, northwest coast of the United States through northern California. [13] [14]

Eastern Mediterranean

In the Eastern Mediterranean, there has been evidence found of paleotsunamis occurring. [15]

List of historic paleotsunamis

YearLocationMain articlePrimary causeDescription
≈1.4 Ma Molokai, Hawaii East Molokai Volcano LandslideOne-third of the East Molokai volcano collapsed into the Pacific Ocean, generating a tsunami with an estimated local height of 2,000 feet (610 m). The wave traveled as far as California and Mexico. [16] [17] [18]
≈9.91–9.29 ka Dor, IsraelUnknownA mega-tsunami had a run of at least 16 metres (52 ft) and traveled between 1.5 and 3.5 km (0.9 and 2.2 mi) inland from the ancient Eastern Mediterranean coast. [19]
≈7000–6000 BC Lisbon, PortugalUnknownA series of giant rocks and cobblestones have been found 14 metres (46 ft) above mean sea level near Guincho Beach. [20]
≈6225–6170 BCNorwegian Sea Storegga Slide LandslideThe Storegga Slides, 100 kilometres (62 mi) northwest of the coast of Møre in the Norwegian Sea, triggered a large tsunami in the North Atlantic Ocean. The collapse involved around 290 kilometres (180 mi) of coastal shelf, and a total volume of 3,500 km3 (840 cu mi) of debris. [21] Based on carbon dating of plant material in the sediment deposited by the tsunami, the latest incident occurred around 6225–6170 BC. [22] [23] In Scotland, traces of the tsunami have been found in sediments from Montrose Basin, the Firth of Forth, up to 80 kilometres (50 mi) inland and 4 metres (13 ft) above current normal tide levels.
5,500 BP Northern Isles Garth tsunami UnknownThe tsunami may have been responsible for contemporary mass burials. [24]
≈1600 BCSantorini, Greece Minoan eruption Volcanic eruptionThe volcanic eruption in Santorini, Greece triggered tsunamis which caused damage to some Minoan sites in eastern Crete.

Current dangers

Scientists continue to find evidence of ancient tsunamis larger than those recorded in historical records. [25]

The tsunami caused by the 2011 Tōhoku earthquake is a prime example of the dangers of ignoring evidence of past tsunamis. It was generated by a megathrust earthquake and made tsunamis up to 40 metres (130 ft) high. It washed over sea walls and drowned over 100 designated tsunami evacuation sites. From historical records, there were three large tsunamis dating back as far as the 17th century, some producing waves dozens of meters high. However, the Japanese based many of their tsunami-defense preparations on smaller tsunamis that had previously hit Japan. In 2011, tsunamis destroyed entire cities, crippling the Fukushima Daiichi Nuclear Power Plant. Over 15,000 people were killed by the tsunami. [5] Not long before the Tōhoku earthquake, the Japanese had set up tsunami stones, warning of tsunami danger. One reads "High dwellings are the peace and harmony of our descendants. Remember the calamity of the great tsunamis. Do not build any homes below this point." [26] [27]

Megatsunami on other planets

The surface of Mars once had oceans but is now dry, and a 2019 study found a paleotsunami may have ravaged some of the surface after a cosmic impact similar to the one that created the Chicxulub crater and likely ended Earth's age of dinosaurs. The impact may have made Pohl Crater. [28] Near where Viking I landed were many boulders, possible debris from a megatsunami, which may have struck perhaps 3.4 billion years ago. The megatsunami could have reached 930 miles (1,500 km) from the impact site, well past Viking 1's landing site. The tsunami may have been 1,640 feet (500 m) high on the ocean, and perhaps 820 feet (250 m) on land. [29]

What happened was possible via two different scenarios, one caused by a 5.6 miles (9.0 km) asteroid meeting "strong ground resistance," releasing 13 million megatons of TNT energy, or a 1.8 miles (2.9 km) asteroid hitting the softer ground, releasing 0.5 million megatons of TNT energy. [30]

See also

Related Research Articles

<span class="mw-page-title-main">Tsunami</span> Series of water waves caused by the displacement of a large volume of a body of water

A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event.

<span class="mw-page-title-main">Megatsunami</span> Very large wave created by a large, sudden displacement of material into a body of water

A megatsunami is a very large wave created by a large, sudden displacement of material into a body of water.

<span class="mw-page-title-main">Juan de Fuca plate</span> Small tectonic plate in the eastern North Pacific

The Juan de Fuca plate is a small tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American plate at the Cascadia subduction zone. It is named after the explorer of the same name. One of the smallest of Earth's tectonic plates, the Juan de Fuca plate is a remnant part of the once-vast Farallon plate, which is now largely subducted underneath the North American plate.

<span class="mw-page-title-main">1700 Cascadia earthquake</span> Megathrust earthquake in the Pacific Northwest region

The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26, 1700, with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The plate slipped an average of 20 meters (66 ft) along a fault rupture about 1,000 kilometers long.

<span class="mw-page-title-main">Cascadia subduction zone</span> Convergent plate boundary that stretches from northern Vancouver Island to Northern California

The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 100–200 km (70–100 mi) off the Pacific coast, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m (98 ft). The Oregon Department of Emergency Management estimates shaking would last 5–7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.

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.

A slow earthquake is a discontinuous, earthquake-like event that releases energy over a period of hours to months, rather than the seconds to minutes characteristic of a typical earthquake. First detected using long term strain measurements, most slow earthquakes now appear to be accompanied by fluid flow and related tremor, which can be detected and approximately located using seismometer data filtered appropriately. That is, they are quiet compared to a regular earthquake, but not "silent" as described in the past.

The 2006 Kuril Islands earthquake occurred on November 15 at 8:14:16 pm JST with a Mw magnitude of 8.3 and a maximum Mercalli intensity of IV (Light) and a maximum Shindo intensity of JMA 2. This megathrust earthquake was the largest event in the central Kuril Islands since 1915 and generated a small tsunami that affected the northern Japanese coast. The tsunami crossed the Pacific Ocean and damaged the harbor at Crescent City, California. Post-tsunami surveys indicate that the local tsunami in the central Kuril Islands reached runups of 21.9 metres (72 ft) or higher.

<span class="mw-page-title-main">Teletsunami</span> Massive tsunamis that strike a thousand kilometers or more from their source

A teletsunami is a tsunami that originates from a distant source, defined as more than 1,000 km (620 mi) away or three hours' travel from the area of interest, sometimes travelling across an ocean. All teletsunamis have been generated by major earthquakes such as the 1755 Lisbon earthquake, 1960 Valdivia earthquake, 1964 Alaska earthquake, 2004 Indian Ocean earthquake, 2011 Tohoku earthquake, and the 2021 South Sandwich Islands earthquakes.

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">1896 Sanriku earthquake</span> Japanese tsunami earthquake

The 1896 Sanriku earthquake was one of the most destructive seismic events in Japanese history. The 8.5 magnitude earthquake occurred at 19:32 on June 15, 1896, approximately 166 kilometres (103 mi) off the coast of Iwate Prefecture, Honshu. It resulted in two tsunami waves which destroyed about 9,000 homes and caused at least 22,000 deaths. The waves reached a then-record height of 38.2 metres (125 ft); this would remain the highest on record until waves from the 2011 Tōhoku earthquake exceeded that height by more than 2 metres.

The 1877 Iquique earthquake occurred at 21:16 local time on 9 May. It had a magnitude of 8.5 on the surface-wave magnitude scale. Other estimates of its magnitude have been as high as 8.9 Mw and 9.0 Mt. It had a maximum intensity of XI (Extreme) on the Mercalli intensity scale and triggered a devastating tsunami. A total of 2,385 people died, mainly in Fiji from the tsunami.

The 869 Jōgan earthquake and its associated tsunami struck the area around Sendai in the northern part of Honshu on 9 July 869. The earthquake had an estimated magnitude of at least 8.6 on the moment magnitude scale, but may have been as high as 9.0, similar to the 2011 Tōhoku earthquake and tsunami. The tsunami caused widespread flooding of the Sendai plain. In 2001, researchers identified sand deposits in a trench more than 4.5 kilometres (2.8 mi) from the coast as coming from this tsunami.

<span class="mw-page-title-main">Tsunami deposit</span> Sedimentary unit deposited by a tsunami

A tsunami deposit is a sedimentary unit deposited as the result of a tsunami. Such deposits may be left onshore during the inundation phase or offshore during the 'backwash' phase. Such deposits are used to identify past tsunami events and thereby better constrain estimates of both earthquake and tsunami hazards. There remain considerable problems, however, in distinguishing between deposits caused by tsunamis and those caused by storms or other sedimentary processes.

<span class="mw-page-title-main">Eltanin impact</span> Prehistoric asteroid impact in southeast Pacific Ocean

The Eltanin impact is thought to be an asteroid impact in the eastern part of the South Pacific Ocean that occurred around the Pliocene-Pleistocene boundary approximately 2.51 ± 0.07  million years ago. The impact occurred at the north edge of the Bellingshausen Sea 1,500 km (950 mi) southwest of Chile, where the sea floor is approximately 4–5 kilometres (2.5–3.1 mi) deep. The asteroid was estimated to be about 1 to 4 km in diameter. No crater associated with the impact has been discovered. The impact likely evaporated 150 km3 (36 cu mi) of water, generating large tsunami waves hundreds of metres high.

The 1420 Caldera earthquake was a pre-Columbian earthquake that shook the southern portion of Atacama Desert in the early morning of August 31, 1420 and caused tsunamis in Chile as well as Hawaii and the towns of Japan. The earthquake is thought to have had a size of 8.8–9.4 Mw. Historical records of the tsunami exist for the Japanese harbours of Kawarago and Aiga where confused residents saw the water recede in the morning of September 1, without any sign of an earthquake. In Chile, rockfalls occurred along the coast as well, producing blocks of up to 40 tons that are now found inland. This is also consistent with the identification of a possible tsunami deposit in Mejillones Bay that has been dated to the range 1409 to 1449. Deposits found by coring of recent sediments in a wetland near Tongoy Bay have also been linked to the 1420 tsunami.

Pachena Bay is located 13 km (8.1 mi) south of Bamfield in Pacific Rim National Park at the southern end of Vancouver Island, British Columbia, Canada. It was the location of a First Nation's village that was destroyed by a tsunami in 1700.

<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.

The Kanto and Tōhoku regions of Japan were struck by major earthquake at midnight on 23 November 1454, which triggered a large tsunami that led to many deaths. It had an estimated magnitude of about 8.4 Mw, based on the extent of observed tsunami deposits.

References

  1. ↑ Pacific Coastal and Marine Science Center (2010). "Tsunami terms". United States Geological Survey. Retrieved January 17, 2024.
  2. ↑ Bressan, David (March 11, 2021). "Century-Old 'Tsunami Stones' Saved Lives In The Tohoku Earthquake Of 2011". Forbes.
  3. ↑ "Tsunami Hazards, Modeling, and the Sedimentary Record". USGS. September 7, 2021.
  4. ↑ Carballeira, R.; Peña‑Monne, J. L.; Otero, X. L.; Sampietro‑Vattuone, M. M.; Castro‑Correa, C. P.; Soto‑Bauerle, M. V.; Pérez‑Alberti3, A. (2022). "Paleotsunami evidence in the Bahía Inglesa coast (Atacama, Chile) based on a multi‑approach analysis" (PDF). Environmental Earth Sciences. 81 (5) (published February 24, 2022): 153. Bibcode:2022EES....81..153C. doi:10.1007/s12665-022-10259-2. S2CID   244212989.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  5. 1 2 3 Scharping, Nathaniel (February 16, 2023). "Chilean coast". Hakai Magazine.
  6. ↑ Yoshinobu, Tsuji (2013). "Catalog of Distant Tsunamis Reaching Japan from Chile and Peru" (PDF). Report of Tsunami Engineering. Archived from the original (PDF) on March 20, 2020.
  7. ↑ Carballeira1, R. (2022). "Paleotsunami evidence in the Bahía Inglesa coast (Atacama, Chile) based on a multi‑approach analysis" (PDF). Environmental Earth Sciences. 81 (5). Bibcode:2022EES....81..153C. doi:10.1007/s12665-022-10259-2. S2CID   244212989.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  8. ↑ Griffiths, James (January 3, 2019). "Ancient tsunami almost wiped out civilization in southern China, study finds". CNN .
  9. ↑ Yoko, Ota (September 26, 2013). "Paleotsunami Study in Taiwan" (PDF).
  10. ↑ Yoko, Ota; Shyu, J. Bruce H.; Wang, Chung-Che; Chung, Ling-Ho; Shen, Chuan-Chou (2015). "Coral boulders along the coast of the Lanyu Island, offshore southeastern Taiwan, as potential paleotsunami records". Journal of Asian Earth Sciences. 114: 588–600. Bibcode:2015JAESc.114..588O. doi:10.1016/j.jseaes.2015.08.001.
  11. ↑ Schulz, Kathryn (July 13, 2015). "The Really Big One". The New Yorker.
  12. ↑ Steele, Bill (September 4, 2012). "Native American Stories expand history" (PDF). Archived from the original (PDF) on July 24, 2015.
  13. ↑ "Searching for Evidence of past Tsunamis in Sediment Cores". Pacific Coastal and Marine Science Center November 23, 2021. November 23, 2021.
  14. ↑ "Central Cascadia subsidence and paleotsunami events for the last ~2,500 years".
  15. ↑ "Evidence for a massive paleo-tsunami at ancient Tel Dor". ScienceDaily.
  16. ↑ "Hawaiian landslides have been catastrophic". mbari.org. Monterey Bay Aquarium Research Institute. October 22, 2015.
  17. ↑ Culliney, John L. (2006) Islands in a Far Sea: The Fate of Nature in Hawaii. Honolulu: University of Hawaii Press. p. 17.
  18. ↑ "Kalaupapa Settlement Boundary Study. Along North Shore to Halawa Valley, Molokai" (PDF). National Park Service. 2001. Retrieved June 29, 2020.
  19. ↑ Shtienberg, Gilad; Yasur-Landau, Assaf; Norris, Richard D.; Lazar, Michael; Rittenour, Tammy M.; Tamberino, Anthony; Gadol, Omri; Cantu, Katrina; Arkin-Shalev, Ehud; Ward, Steven N.; Levy, Thomas E. (December 23, 2020). "A Neolithic mega-tsunami event in the eastern Mediterranean: Prehistoric settlement vulnerability along the Carmel coast, Israel". PLOS ONE. 15 (12). e0243619. Bibcode:2020PLoSO..1543619S. doi: 10.1371/journal.pone.0243619 . ISSN   1932-6203. PMC   7757801 . PMID   33362214.
  20. ↑ Baptista, M. A.; Miranda, J. M. (2009). "Revision of the Portuguese catalog of tsunamis" (PDF). Nat. Hazards Earth Syst. Sci. 9 (1): 25–42. Bibcode:2009NHESS...9...25B. doi: 10.5194/nhess-9-25-2009 . Archived (PDF) from the original on April 3, 2013. Retrieved September 30, 2012.
  21. ↑ Bondevik, Stein; Dawson, Sue; Dawson, Alastair; Lohne, Øystein (August 5, 2003). "Record-breaking Height for 8000-Year-Old Tsunami in the North Atlantic" (PDF). Eos, Transactions, American Geophysical Union. 84 (31): 289, 293. Bibcode:2003EOSTr..84..289B. doi: 10.1029/2003EO310001 . hdl:1956/729. Archived (PDF) from the original on August 7, 2011.
  22. ↑ Bondevik, S; Lovholt, F; Harbitz, C; Stormo, S; Skjerdal, G (2006). "The Storegga Slide Tsunami – Deposits, Run-up Heights and Radiocarbon Dating of the 8000-Year-Old Tsunami in the North Atlantic". American Geophysical Union meeting.
  23. ↑ Bondevik, S; Stormo, SK; Skjerdal, G (2012). "Green mosses date the Storegga tsunami to the chilliest decades of the 8.2 ka cold event". Quaternary Science Reviews. 45: 1–6. Bibcode:2012QSRv...45....1B. doi:10.1016/j.quascirev.2012.04.020.
  24. ↑ Cain, Genevieve; Goff, James; McFadgen, Bruce (June 1, 2019). "Prehistoric Coastal Mass Burials: Did Death Come in Waves?". Journal of Archaeological Method and Theory. 26 (2): 714–754. doi: 10.1007/s10816-018-9386-y . ISSN   1573-7764.
  25. ↑ Scharping, Nathaniel (February 18, 2023). "Paleotsunamis Offer a Quiet Warning". The Atlantic.
  26. ↑ Lewis, Danny (August 31, 2015). "These Century-Old Stone "Tsunami Stones" Dot Japan's Coastline". Smithsonian.
  27. ↑ Bressan, David (March 11, 2021). "Century-Old 'Tsunami Stones' Saved Lives In The Tohoku Earthquake Of 2011". Forbes.
  28. ↑ Zastrow, Mark (December 6, 2022). "Megatsunami swept over Mars after devastating asteroid strike". Astronomy.
  29. ↑ Ashley, Strickland (December 2, 2022). "NASA's Viking 1 may have landed at the site of an ancient Martian megatsunami". cnn.com.
  30. ↑ Ashley, Strickland (December 2, 2022). "NASA's Viking 1 may have landed at the site of an ancient Martian megatsunami". CNN .
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