2011 Sendai Earthquake And Tsunami, Tōhoku Region, Pacific Ocean

Geophysical impact
According to Italy's National Institute of Geophysics and Volcanology, the earthquake's enormous strength shifted the Earth's axis by 25 centimeters (9.8 in). This deviation led a number of small changes, including those to the length of a day and the tilt of the Earth. The speed of the Earth's rotation increased, shortening the day by 1.8 microseconds due to the redistribution of Earth's mass.
A report by the U.S. Geological Survey said that Honshu, the main island of Japan, was shifted 5 m (16 ft) toward the east. Researcher Lucy Jones said of the precise data, "The Japanese have the best seismic information in the world... This is overwhelmingly the best-recorded great earthquake ever."
Shinmoedake, a volcano in Kyushu, erupted two days after the earthquake. Although previous eruptions of the volcano occurred in January 2011, it is not known if the earthquake had triggered a renewed eruption.