Link #100: The 2011 Pacific Earthquake Moved Japan 8 Feet to the East!

Aug 3, 2015

Link #100: The 2011 Pacific Earthquake Moved Japan 8 Feet to the East!

Map_of_Sendai_Earthquake_2011 — Map of the Tōhoku earthquake and aftershocks on 11–14 March. Public domain according to http://www2.demis.nl

Japan is historically connected to earthquakes. The reason for this is that Japan is located in a region that is specifically prone to earthquakes. In our last post, we spoke about how more than 11,500 buildings in Niigata got destroyed or damaged because of an earthquake that struck off the north western shore of Japan.

However, that wasn’t even the most severe earthquake that Japan has experienced. The most severe earthquake that Japan ever faced was probably the one that hit the region in 2011. In fact, the 2011 earthquake was so strong that it moved Japan eastwards and closer to the North American continent!

Why Did the 2011 Japan Earthquake Move Japan Eastwards?

The 2011 earthquake is also known as the Great East Japan Earthquake, the 3.11 Earthquake and the 2011 Tohoku Earthquake. These names are used for this earthquake because it struck approximately 70 kilometres off the eastern coast of Tohoku.

The earthquake was caused when two relevant tectonic plates (plates on which continents rest) – the North American tectonic plate and the Pacific tectonic plate – collided. The earthquake measured 9.0 on the Richter scale.

Earth’s tectonic plates move very slowly but generate a lot pressure and energy. When they collide, a lot of this energy is released in the form of land-based vibrations and water-based tsunamis.

According to geologists, the collision resulted in subduction which is a process where one tectonic plate is pushed under another tectonic plate. While it isn’t clear which plate went under which plate, it’s well established that this was one of the major reasons why this earthquake ended up moving Japan eastwards.

How Much Did Japan Move Because of the 2011 Earthquake?

Honshu_Island_in_Japan — Honshu Island locator map by Kikos, (CC BY-SA 3.0)

The earthquake didn’t move the whole country of Japan, but moved only a part of it. However, it was the main island of Japan – Honshu – that was moved eastwards by the earthquake. Honshu shifted by 8 feet or 2.4 metres because of the earthquake.

It wasn’t only the Japanese island of Honshu that was moved by the earthquake. In fact, this earthquake was strong enough to affect the whole planet. It ended up changing the Earth’s axis too.

With this shift, the speed with which the planet rotates changed too. Furthermore, the changed speed resulted in a changed duration as well. The earthquake reduced one Earth day by 1.8 millionths of a second.

How Much Damage Did the 2011 Japan Earthquake Cause?

US_Navy_110318-N-0076O-004_An_aerial_view_of_damage_to_northern_Honshu,_Japan,_after_a_9.0_magnitude_earthquake_and_subsequent_tsunami_devastated — NORTH HONSHU, Japan (March 18, 2011) An aerial view of damage to northern Honshu, Japan, after a 9.0 magnitude earthquake and subsequent tsunami devastated the area. U.S. Navy photo by Naval Air Crewman 1st Class Jay Okonek, PD image.

The 2011 Japan earthquake is considered to be the worst earthquake to have ever hit Japan in terms of power. On the same basis, it is considered to be fourth worst earthquake ever to have been recorded on Earth since the beginning of the 20th century when recordkeeping began.

All this power had an impact on the ground too. This earthquake claimed the lives of almost 16,000 people and injured more than 6,000. In addition to this, about 2,600 went missing because of this earthquake which also ended up creating tsunami waves as high as 133 feet.

The earthquake also ended up destroying more than 127,000 buildings completely, partially destroying almost 273,000 buildings and damaging almost 748,000 buildings.