The Korean Peninsula has moved a 5 centimetres to the east due to the massive quake that rocked Japan last week, a state-run astronomical institute said today.

The Korea Astronomy and Space Science Institute (KASI) said that based on detailed global positioning system (GPS) data, the peninsula moved between 1 cm to 5 cm depending on the location, with Ulleung Island and nearby Dokdo islets in the East Sea being most affected.

The south-western part of the country and Jeju Island off the peninsula’s southern coast moved far less.

Ulleung and Dokdo are the closest South Korean territories to the epicentre of the 9.0 magnitude tremor that devastated the north-eastern part of Honshu Island on Friday.

The epicentre was located 130 kilometres east of Sendai city under the Pacific Ocean.

“We are trying to determine if the movement was a one-time event directly related to the tremor or is ongoing,” KASI said. “The reading used information provided by 11 GPS stations out of 90 operated in the country.”

The institute, meanwhile, said that the Japan moved roughly 2 meters to the east.