[7] The earthquake had a magnitude of 7.4 according to the Japanese Meteorological Agency (JMA), while the United States Geological Survey (USGS) gave an estimate of 7.3.

[6] The Pacific plate, made of oceanic lithosphere, subducts beneath the Okhotsk microplate along a convergent boundary located off the east coast of the northern half of Japan.

This subduction zone can produce megathrust earthquakes with magnitudes greater than 8.5, as evident in historical records.

An analysis of the February 2021 earthquake suggest reverse faulting within the downgoing Pacific plate beneath the subduction interface.

[16] This shallow-focus earthquake occurred as a result of reverse faulting at a depth of 57 or 63.1 km within the Pacific plate.

[13] A finite fault model by the USGS indicate the main rupture patch was an oval-shaped area situated at a depth of 50–70 km (40 × 20 km2).

The two shocks have been categorized as a doublet earthquake due to their close location, timing of occurrence, and magnitude.

[24] An earthquake light manifested in downtown Sendai, coinciding with a magnetic disturbance detected by a geomagnetic observatory in Kakioka, Ibaraki Prefecture.

[13][26] The deep focal depth of the event, as well as its magnitude, resulted in strong shaking across the Tōhoku and Kantō regions.

[27] According to the National Research Institute for Earth Science and Disaster Prevention, a seismic intensity of close to Shindo 7 was recorded at Soma and Kunimi, Fukushima.

[2] Class IV was assigned to northern Miyagi on the JMA long period ground motion scale.

[31] A tsunami measuring 20 cm was recorded by the JMA at Ishinomaki Port, Miyagi at 00:29 local time.

A horse racing facility in Fukushima City suffered water leakage and damage to the walls.

[39] The Inari Shrine in the city was also affected; three stone lanterns restored following last year's earthquake were destroyed.

[42] The White Cube, a concert hall and sports center in Shiroishi suffered a partial collapse of its ceiling.

[45] The Ministry of Land, Infrastructure, Transport and Tourism reported that there were 25 cases of people trapped in elevators in the Greater Tokyo Area.

A Sapporo Breweries factory in Natori suspended beer production after damage to machines was reported.

Instances of water bursting from pipes caused significant damage at the company's Sendai, Honmiya and Koriyama factories.

Productions at other factories belonging to companies including Toyota, Nissan, Kioxia, and Renesas Electronics were also impacted.

[64] A 100-meter-long crack and zone of uplift was observed on the Tōhoku Expressway between the Shiroishi interchange and Kunimi toll stop.

[47] The Tadamigawa Bridge over the Abukuma River in Date was uplifted by several tens of centimeters, making it impassable.

[74] Investigations by the National Police Agency concluded that the earthquake only resulted in one confirmed death; the victim from Tome.

[70] Six people in Saitama, five each in Kanagawa, Iwate and Yamagata, eight and Ibaraki, three in Chiba, two each in Yamanashi and Tochigi, and one each in Akita and Niigata, were injured.

[32] A tsunami advisory was issued along the coasts of Miyagi and Fukushima prefectures following the earthquake, causing evacuations.

Officials stated that changes in tide levels at the coasts of Fukushima, Miyagi, and Iwate prefectures can be expected without damage.

[35] Chief Cabinet Secretary Hirokazu Matsuno said in a press conference on March 17 that a Disaster Relief Act would be in effect in every municipality of Fukushima and Miyagi.

[76] The Japan Self-Defense Forces was deployed to Fukushima and Miyagi prefectures at the request of their respective governors to restore essential lifelines.

[80] At the Fukushima Daini Nuclear Power Plant, the pumps in the spent fuel pools of Units 1 and 3 had stopped working.

[82] Residents have been urged to stay alert about the threat of landslides and avalanches as heavy rain and snowfall are expected to hit the Tōhoku region until March 19.

Weathernews stated that due to the earthquake, steep slopes may have been destabilized, and areas with heavy snowfall are at risk of experiencing avalanches.