A deep-sea submersible has found cracks in the seabed off the coast of Japan believed to be the result of the March 11 earthquake, officials said. The Shinkai 6500 submersible surveyed three sites on the seabed in an area near the Japan Trench and found cracks of the coastline of Iwate, Miyagi and Fukushima prefectures, the Yomiuri Shimbun reported Tuesday. Researchers said they believed the cracks were made by the March earthquake because a survey of the same area five years ago did not reveal any cracks. \"We found more cracks this time than after previous earthquakes,\" Katsunori Fujikura of the Japan Agency For Marine-Earth Science and Technology said. \"We want to continually monitor the seabed.\" The cracks were found at depths between 10,500 feet and 18,000 feet, the researchers said.