Durham Scientist Joins International Team to Investigate 2011 Tohoku Earthquake

A Durham scientist is part of an international team aboard the Chikyu vessel investigating the 2011 Tohoku earthquake. Their research aims to understand the seismic processes by drilling the Japan Trench and analyzing fault samples. This follows earlier studies that highlighted unusual fault behavior, challenging previous geological theories about subduction zone quakes.

A scientist from Durham University is currently participating in a global research initiative aboard the Chikyu drilling vessel, which is engaged in probing the seabed off Japan’s east coast. This project is focused on gaining insights into the catastrophic 2011 Tohoku earthquake, renowned for its significant scale and the devastating tsunami it triggered, resulting in extensive damage and loss of life. The research team is systematically drilling through geological layers to collect sediment samples and analyze fault properties related to the event.

The Tohoku earthquake, which occurred in 2011, stands as one of the most significant seismic events in recent history. Its aftermath included a tsunami that inundated Japanese coastline, severely affecting infrastructure and leading to the Fukushima nuclear disaster. During this tragic event, approximately 18,500 individuals lost their lives, and over 160,000 people were displaced.

In a prior investigation conducted in 2013, the Japan Trench Fast Drilling Project (JFAST) acquired samples from the Japan Trench to understand better the earthquake’s underlying causes. Following this, current efforts under the Tracking Tsunamigenic Slip Across the Japan Trench (JTRACK) project involve further in-depth examination. The team, of which Durham’s Dr. Rebecca Robertson is a part, is well into their four-month expedition and has successfully drilled through critical geological boundaries to collect invaluable data.

At this stage of their expedition, the team has established an observatory through the fault zone, facilitating the sampling of deep-sea sediment and fault material. They are also capturing detailed imaging of the fault area, which will be evaluated alongside the collected samples. The JTRACK initiative aims to deepen the scientific understanding of the mechanisms that resulted in the unprecedented fault movement during the Tohoku earthquake.

The geological understanding prior to the 2011 earthquake posited that subduction zones, known for generating formidable quakes, possessed a shallow fault segment that remained stable. However, the Tohoku earthquake challenged this notion, demonstrating significant displacement from a single rupture, extending all the way to the seabed. Through meticulous analysis of the section of the fault that exhibited this unusual slip, the JTRACK team endeavors to uncover critical insights into such geological phenomena.

The Tohoku earthquake, which struck Japan in 2011, is historically significant due to the immense destruction it caused, including a tsunami that devastated parts of the coastline and resulted in a nuclear disaster at Fukushima. This earthquake led to a reassessment of geological beliefs regarding fault behavior in subduction zones, where one tectonic plate moves beneath another. Previous understandings indicated that only the deeper segments of these faults were prone to rupture, but the Tohoku earthquake involved unprecedented shallow fault slip, prompting further investigation into tectonic processes. Research projects like JFAST and JTRACK aim to provide valuable geological data to better understand these events and improve seismic risk assessments.

In summary, the ongoing JTRACK expedition led by Durham University’s Dr. Rebecca Robertson is a vital contribution to the study of earthquakes, particularly the 2011 Tohoku event. By gathering and analyzing sediment and fault material from the Japan Trench, the research team aims to illuminate the factors contributing to this significant geological event. The insights gleaned from this research could potentially enhance future earthquake preparedness and response strategies.

Original Source: www.durham.ac.uk