PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

A manned submersible found a fault scarp of the 2011 Tohoku-oki megaquake in the Japan Trench

A manned submersible found a fault scarp of the 2011 Tohoku-oki megaquake in the Japan Trench
2024-01-17
(Press-News.org)

Niigata, Japan – On September 4, 2022, a geologist Hayato Ueda in Niigata University boarded a submarine vehicle with a pilot Chris May and had a dive into the Japan Trench within the epicenter area of the 2011 Tohoku-oki megaquake, which caused the devastating tsunami disaster. On the 7,500 m deep trench bottom, they found a 26 m high nearly vertical cliff on the eastern slope of a 60 m high ridge. Previous bathymetric surveys from the sea surface have revealed that the ridge did not exist before, and appeared just after the megaquake accompanied with a fault on its eastern flank. He and his colleague scientists on deck thus concluded that the cliff was a surface expression of a coseismic movement of the fault. The cliff consisted of unconsolidated soft mud. The lower slope than the cliff was occupied by abundant debris of the same soft mud blocks, which obviously supplied from the cliff. The observed sharp fracture surfaces and highly angular edges, both on the cliff and debris blocks, imply very quick increase of stress that fractured the soft muds before they plastically flowed, and thus support a coseismic origin of the cliff.

The vehicle traversed the ridge across the fault precisely measuring the topography using acoustic transponder and pressure gauge. The height and uplifted volume of the ridge both suggest a coseismic slip of the fault as large as 80–120 m (the value depends on the assumed dip angle of the underlying fault) in the Japan Trench. This estimation is greater than the previously estimated fault slip (~65 m) beneath the slope on the west of the trench axis. They attributed the excess fault slip in the trench to local enhancement owing to the uneven top surface of the subducting Pacific plate, which modified the fault geometry and stability.

The 2011 megaquake resulted from rupture and slip of the plate boundary fault between the northeast Honshu Island of Japan (Okhotsk plate) and the subducting Pacific plate. After the earthquake, many geodetic and geophysical studies have proposed that this coseismic fault movement probably propagated to the trench. Because topographic change by near-surface fault movement is one of the major causes of tsunamis, it is important to precisely know what occurred in the deep-sea trench when the trench-type earthquake such as the 2011 event occurred. However, because of great depths, no submersible vehicles (neither manned nor remotely operated) had been able to access to the Japan Trench bottom. This study was the first time to observe, visually record, and precisely measure the topographic change (including fault cliff) in the trench by a single trench-type megaquake event. It verified that the fault slip surely propagated to the surface at the 2011 event, and deduced that the amount of the slip was at least locally as great as 100 m. These results are expected to contribute to our understanding of genesis and to hazards of tsunamis triggered by trench-type earthquakes. This study was published by the journal communications earth & environment on Dec. 26, 2023 (https://doi.org/10.1038/s43247-023-01118-4).

END


[Attachments] See images for this press release:
A manned submersible found a fault scarp of the 2011 Tohoku-oki megaquake in the Japan Trench A manned submersible found a fault scarp of the 2011 Tohoku-oki megaquake in the Japan Trench 2

ELSE PRESS RELEASES FROM THIS DATE:

Video gamers worldwide may be risking irreversible hearing loss and/or tinnitus

2024-01-17
Video gamers worldwide may be risking irreversible hearing loss and/or tinnitus—persistent ringing/buzzing in the ears—finds a systematic review of the available evidence, published in the open access journal BMJ Public Health.   What evidence there is suggests that the sound levels reported in studies of more than 50,000 people often near, or exceed, permissible safe limits, conclude the researchers.  And given the popularity of these games, greater public health efforts are needed to raise awareness of the potential ...

Enlarged breast tissue in men (gynaecomastia) linked to heightened risk of death

2024-01-17
Men with enlarged breast tissue, not caused by excess weight—a condition formally known as gynaecomastia—may be at heightened risk of an early death before the age of 75, suggests the first study of its kind, published online in the open access journal BMJ Open.   Those with a pre-existing risk factor, such as cancer or circulatory, lung, and gut diseases before diagnosis seem to be most vulnerable, the findings indicate. Enlarged breast tissue in men is usually caused by a hormone imbalance and affects around a third to around two thirds of men, depending on age. It is distinct from what is often dubbed ...

Same-level workplace falls set to rise amid surge in older female workforce numbers

2024-01-17
Same-level falls in the workplace are set to rise amid rapid growth in the numbers of older female employees in the workforce, suggests Australian research published online first in the journal Occupational & Environmental Medicine. Although workplace falls, overall, are more common among male employees, particularly falls from height, same-level falls are more common in older women, the findings indicate. The prevalence and relative severity of workplace falls mean that better prevention strategies are needed to mitigate these sex-specific risk factors, conclude the researchers. In 2016, an estimated 1.53 million deaths and 76.1 million years of ...

Silkmoths: Different olfactory worlds of females and males

Silkmoths: Different olfactory worlds of females and males
2024-01-17
The world smells different for female silkmoths than for males In humans, the sense of smell is similarly developed in men and women, although women have slightly more olfactory neurons and therefore a slightly more sensitive nose. On the whole, however, they perceive the same odors. Male moths, on the other hand, live in a completely different olfactory world to their female counterparts. For example, the antennae of male silkmoths - their "nose" - are highly specialized to detect female sex pheromones, ...

Wrongly-enforced rules over “digital surrogates” by museums censors research and creative use, study warns

2024-01-17
Cultural institutions are censoring research, learning and creativity because of the way they police the reuse of digital copies of out-of-copyright artworks and artefacts, a new study warns. Cultural institutions have created a “mess” by claiming and enforcing new rights over the reproduction images of works in their collections. This allows museums and other organisations to refuse requests for the use of the images in education or research or charge high fees. This impedes free and creative expression and amounts to censorship, according to Dr Andrea Wallace from the University of Exeter Law School. Researchers, educators and others regularly ...

Space solar power project ends first in-space mission with successes and lessons

Space solar power project ends first in-space mission with successes and lessons
2024-01-17
One year ago, Caltech’s Space Solar Power Demonstrator (SSPD-1) launched into space to demonstrate and test three technological innovations that are among those necessary to make space solar power a reality. The spaceborne testbed demonstrated the ability to beam power wirelessly in space; it measured the efficiency, durability, and function of a variety of different types of solar cells in space; and gave a real-world trial of the design of a lightweight deployable structure to deliver and hold the aforementioned solar cells and power transmitters. Now, with ...

Pediatric Cancer Research Foundation launches 2024 call for entries for scholarships for pediatric cancer survivors

2024-01-17
The Pediatric Cancer Research Foundation today announced a call for entries for its 2024 Cancer Survivor Scholarships.  The Foundation will award $100,000 to eligible students – including graduating high school seniors, college, vocational and graduate students – to support these students in realizing happy, productive futures. “Beating cancer medically is just one part of creating a healthy, happy life.  Achieving our purpose of ensuring survivors can spread their wings and soar requires ...

Novel drug for fatal type of heart failure proves safe and effective in phase 3 trial

Novel drug for fatal type of heart failure proves safe and effective in phase 3 trial
2024-01-17
Pumping over 100,000 times a day, the heart is a critical muscle needed to deliver oxygen and nutrients to our organs to sustain healthy bodily function. Unfortunately, heart failure affects an estimated 6.2 million people in the U.S. and a staggering 64 million worldwide. Of older patients with heart failure and abnormally thickened hearts, as many as one in five have an underdiagnosed, highly progressive and fatal condition called transthyretin amyloid cardiomyopathy, or ATTR-CM. The disease, which can be hereditary or develop spontaneously, is defined by an accumulation of misfolded transthyretin ...

Study reveals a reaction at the heart of many renewable energy technologies

Study reveals a reaction at the heart of many renewable energy technologies
2024-01-16
CAMBRIDGE, MA — A key chemical reaction — in which the movement of protons between the surface of an electrode and an electrolyte drives an electric current — is a critical step in many energy technologies, including fuel cells and the electrolyzers used to produce hydrogen gas. For the first time, MIT chemists have mapped out in detail how these proton-coupled electron transfers happen at an electrode surface. Their results could help researchers design more efficient fuel cells, batteries, or other energy technologies. “Our advance in this paper was studying and understanding the nature of how these electrons and protons couple ...

Water as a nonlinear medium for ultrabroadband white laser

Water as a nonlinear medium for ultrabroadband white laser
2024-01-16
Scientists are making significant strides in the development of ultrabroadband white laser sources, covering a wide spectrum from ultraviolet to far infrared. These lasers find applications in diverse fields such as large-scale imaging, femto-chemistry, telecommunications, laser spectroscopy, sensing, and ultrafast sciences. However, the pursuit faces challenges, particularly in the selection of appropriate nonlinear mediums. Traditional solid materials, while efficient, are prone to optical damage under high peak power conditions. Gas mediums, though ...

LAST 30 PRESS RELEASES:

Scientists trace origins of now extinct plant population from volcanically active Nishinoshima

AI algorithm based on routine mammogram + age can predict women’s major cardiovascular disease risk

New hurdle seen to prostate screening: primary-care docs

MSU researchers explore how virtual sports aid mental health

Working together, cells extend their senses

Cheese fungi help unlock secrets of evolution

Researchers find brain region that fuels compulsive drinking

Mental health effects of exposure to firearm violence persist long after direct exposure

Research identifies immune response that controls Oropouche infection and prevents neurological damage

University of Cincinnati, Kent State University awarded $3M by NSF to share research resources

Ancient DNA reveals deeply complex Mastodon family and repeated migrations driven by climate change

Measuring the quantum W state

Researchers find a way to use antibodies to direct T cells to kill Cytomegalovirus-infected cells

Engineers create mini microscope for real-time brain imaging

Funding for training and research in biological complexity

The Journal of Nuclear Medicine Ahead-of-Print Tip Sheet: September 12, 2025

ISSCR statement on the scientific and therapeutic value of human fetal tissue research

Novel PET tracer detects synaptic changes in spinal cord and brain after spinal cord injury

Wiley advances Knowitall Solutions with new trendfinder application for user-friendly chemometric analysis and additional enhancements to analytical workflows

Benchmark study tracks trends in dog behavior

OpenAI, DeepSeek, and Google vary widely in identifying hate speech

Research spotlight: Study identifies a surprising new treatment target for chronic limb threatening ischemia

Childhood loneliness and cognitive decline and dementia risk in middle-aged and older adults

Parental diseases of despair and suicidal events in their children

Acupuncture for chronic low back pain in older adults

Acupuncture treatment improves disabling effects of chronic low back pain in older adults

How interstellar objects similar to 3I/ATLAS could jump-start planet formation around infant stars

Rented e-bicycles more dangerous than e-scooters in cities

Ditches as waterways: Managing ‘ditch-scapes’ to strengthen communities and the environment

In-situ molecular passivation enables pure-blue perovskite LEDs via vacuum thermal evaporation

[Press-News.org] A manned submersible found a fault scarp of the 2011 Tohoku-oki megaquake in the Japan Trench