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.
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.
The 1993 southwest-off Hokkaido earthquake or Okushiri earthquake occurred at 13:17:12 UTC on 12 July 1993 in the Sea of Japan near the island of Hokkaido. It had a magnitude of 7.7 on the moment magnitude scale and a maximum felt intensity of VIII (Severe) on the Mercalli intensity scale. It triggered a major tsunami that caused deaths on Hokkaidō and in southeastern Russia, with a total of 230 fatalities recorded. The island of Okushiri was hardest hit, with 165 casualties from the earthquake, the tsunami and a large landslide.
On 11 March 2011, at 14:46 JST, a 9.0–9.1 undersea megathrust earthquake occurred in the Pacific Ocean, 72 km (45 mi) east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes and caused a tsunami. It is sometimes known in Japan as the "Great East Japan Earthquake", among other names. The disaster is often referred to by its numerical date, 3.11.
A potent magnitude 6.6 Mw intraplate aftershock occurred at 17:16 JST (08:16 UTC) on 11 April, in the Hamadōri region of Fukushima, Japan. With a shallow focus of 13 km (8.1 mi), the earthquake was centred inland about 36 km (22 mi) west of Iwaki, causing widespread strong to locally severe shaking. It was one of many aftershocks to follow the 11 March Tōhoku earthquake, and the strongest to have its epicentre located inland.
The 2016 Fukushima earthquake struck Japan east-southeast of Namie, Fukushima Prefecture at 05:59 JST on November 22 with depth of 11.4 km (7.1 mi). The shock had a maximum intensity of VII (Very strong) on the Mercalli scale. The earthquake was initially reported as a 7.3 magnitude by Japan Meteorological Agency, and was later revised to 7.4, while the United States Geological Survey and GFZ Potsdam determined a magnitude of 6.9.
The 1898 Mare Island earthquake occurred in Northern California on with a moment magnitude of 5.8–6.4 and a maximum Mercalli intensity of VIII–IX (Severe–Violent). Its area of perceptibility included much of northern and central California and western Nevada. Damage amounted to $350,000 and was most pronounced on Mare Island, a peninsula in northern San Francisco Bay. While relatively strong effects there were attributed to vulnerable buildings, moderate effects elsewhere in the San Francisco Bay Area consisted of damaged or partially collapsed structures, and there were media reports of a small tsunami and mostly mild aftershocks that followed.
The 2017 Pohang earthquake (浦項地震), measuring magnitude 5.4 on the Richter scale, struck Heunghae, Pohang, North Gyeongsang Province, South Korea on November 15, 2017, and the epicenter was 7 km above the surface. It is tied with the 2016 Gyeongju earthquake as the country's strongest earthquake in modern history since seismological observations started in Korea in 1978, and the most destructive ever recorded with "an estimated 300 billion won in damage.". It also recorded a VII intensity on the Modified Mercalli intensity scale, making it the second largest earthquake in recorded history in Korea.
The 1927 Lompoc earthquake occurred on November 4 at 05:49 PST with an epicenter off the coast of Santa Barbara County Southern California. The earthquake measured 7.0 on the moment magnitude scale and had a maximum Modified Mercalli intensity of IX (Violent). It caused widespread damage in several towns of Santa Barbara County. A 2 m tsunami damaged railroad infrastructure and was recorded in Hawaii. There were no injuries or deaths from the earthquake.
An earthquake struck near the Hawaiian island of Lanai on February 19, at 10:11 pm HST with an estimated magnitude of 7.5 on the moment magnitude scale (Mw ). It remains one of the largest seismic event to hit the Hawaiian Islands since the 1868 Kaʻū earthquake, with its effects being felt throughout the entire archipelago. It caused severe damage on the islands of Lanai, Molokai and Maui. A tsunami may have been generated however there are speculations if it had actually happened. Despite the size of the quake and the extent of damage, there were no deaths.
On March 20, 2021, at 18:09 JST. The magnitude 6.9 or 7.0 earthquake struck offshore east of Tōhoku, Japan at a depth of 54.0 kilometers (33.6 mi) to 60 kilometers (37 mi). It had a maximum JMA intensity of Shindo 5+ while on the Mercalli intensity scale, it earned a rating of VII. Power outages and some slight damage in Miyagi was reported.
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 ).
On April 13, 1923, at 15:31 UTC, an earthquake occurred off the northern coast of the Kamchatka Peninsula in the USSR, present-day Russia. The earthquake had a surface-wave magnitude (Ms ) of 6.8–7.3 and an estimated moment magnitude (Mw ) of 7.0–8.2. This event came just two months after a slightly larger earthquake with an epicenter struck south of the April event. Both earthquakes were tsunamigenic although the latter generated wave heights far exceeding that of the one in February. After two foreshocks of "moderate force", the main event caused considerable damage. Most of the 36 casualties were the result of the tsunami inundation rather than the earthquake.
On December 5, 1456, the largest earthquake to occur on the Italian Peninsula struck the Kingdom of Naples. The earthquake had an estimated moment magnitude of Mw 7.19–7.4, and was centred near the town of Pontelandolfo in the present-day Province of Benevento, southern Italy. Earning a level of XI (Extreme) on the Modified Mercalli intensity scale, the earthquake caused widespread destruction in central and southern Italy. Estimates of the death toll range greatly with as many as 70,000 deaths reported. It was followed by two strong Mw 7.0 and 6.0 earthquakes to the north on December 30. The earthquake sequence is considered the largest in Italian history, and one of the most studied.
The 1743 Salento earthquake affected the Apulian region of southwestern Italy on 20 February at 23:30 IST. The ~7.1 Mw earthquake had an epicenter in the Adriatic and Ionian seas, off the coast of modern-day Lecce and Brindisi provinces in Salento. It had a maximum Modified Mercalli intensity of IX (Violent), causing heavy damage in Nardò. Damage was also reported across the sea, in the Balkans. The earthquake also generated a tsunami of up to 11 meters in run-up. Between 180 and 300 people were killed in the disaster.
On 29 November, at 14:10 UTC, a magnitude 7.7 earthquake struck off the southern coast of Taliabu Island Regency in North Maluku, Indonesia. At least 41 people were killed on the nearby islands and a tsunami was triggered. Several hundred homes, buildings and offices were damaged or destroyed.
An earthquake struck present-day North Korea during the Joseon Dynasty. The earthquake had an estimated moment magnitude of 7.3 and affected present-day North Hamgyong Province. The maximum Modified Mercalli intensity was assigned VIII to IX. Eighty-three homes collapsed and livestock were destroyed. A landslide killed at least two people while additional fatalities occurred during a stampede.
The 779 Gyeongju earthquake struck present-day South Korea during the Silla kingdom. It one of the deadliest earthquake in Korean history, and one of the largest earthquake to occur inland on the Korean Peninsula between the years 2 AD and 1904. The earthquake had an estimated moment magnitude of 6.7 to 7.0, and affected present-day North Gyeongsang Province. The maximum Modified Mercalli intensity was assigned IX. More than 100 people died and many houses collapsed. This earthquake occurred close to the epicenter of the 2016 Gyeongju earthquake.
On 8 August 2024, at 16:42:55 JST, a 7.1 earthquake struck in the Hyūga Sea off the coast of Miyazaki Prefecture, Kyushu, Japan, 20 km (12 mi) northeast of Nichinan.
