Beneath the waters off Japan¡¯s northeastern coast where two tectonic plates converge, scientists aboard a research vessel are investigating the causes of one of the most powerful earthquakes in recorded history by drilling to a total depth of 7,877.5 meters below sea level.

Operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the deep-sea drilling vessel Chikyu ¡ª one of only two such ships in the world dedicated solely to scientific research ¡ª has embarked on a 106-day expedition to investigate the Japan Trench subduction zone, approximately 200 kilometers off the coast of Miyagi Prefecture, a journey that the researchers aim to complete by Dec. 20.

Researchers hope to piece together the earthquake¡¯s story and assess the potential for the fault ¡ª the same one that triggered the 2011 Great East Japan Earthquake ¡ª to cause another massive quake in the future.