Fault and Crustal Dynamics Group

Geodynamics · Rock Rheology · Earthquake Science

Jun Muto Laboratory

Deciphering the Mechanics of the Restless Earth

Professor, Department of Earth Science
Graduate School of Science & International Research Institute of Disaster Science
Tohoku University, Sendai, Japan
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About

From Minerals to Megathrust

Our laboratory investigates the complex deformation of the Earth's crust and mantle by integrating laboratory rock deformation experiments, geological field observations, geodetic data analysis, and computational simulations. We aim for a comprehensive, multi-scale understanding of Earth's deformation — from atomic-scale crystal defects to the dynamics of megathrust earthquakes.

Since the 2011 Tohoku-Oki earthquake (Mw 9.0), a central question of our research has been: how do the fundamental deformation processes of rocks connect to the postseismic behavior of a giant subduction zone? By bridging rock mechanics with geodesy, we pursue answers that span from the laboratory bench to the entire island arc.

91+
Publications
27
Funded Projects

Keywords

Rock Rheology Fault Mechanics Postseismic Deformation Viscoelastic Relaxation GNSS Geodesy Radon Monitoring Subduction Zone Fracture & Friction Deformation Experiments Transient Creep NE Japan Arc Seismic Cycle
Core Research

Three Pillars of Investigation

Our research is organized around three interconnected themes, each addressing a critical aspect of how the Earth deforms — from the grain scale to the arc scale.

Fault & Rock Rheology

Fracture · Friction · Flow

We investigate the fundamental deformation behavior of crustal and mantle rocks through high-temperature, high-pressure experiments using a Griggs-type deformation apparatus. Our research spans the brittle-plastic transition of quartz-feldspar systems, frictional instabilities in simulated fault gouges, dehydration-induced slip behavior, and phase-transformation faulting — addressing the full spectrum from shallow seismogenic faults to deep-focus earthquakes. We are also advancing research on the high-strain-rate deformation characteristics of rocks using an impact testing apparatus, simulating seismic rupture propagation.

Postseismic Deformation & Crustal Rheology

Viscoelastic Relaxation · Afterslip · Transient Flow

The 2011 Tohoku-Oki earthquake provides an unprecedented natural laboratory. Using rock-mechanics-based rheological models with laterally varying viscosity and nonlinear flow laws, we decode the postseismic deformation observed by Japan's dense GNSS network. Our work reveals the heterogeneous rheological structure of the NE Japan arc — including low-viscosity zones beneath Quaternary volcanoes — and the mechanical coupling between afterslip and transient mantle flow.

Crustal Deformation Monitoring & Forecasting

Atmospheric Radon · GNSS · Machine Learning

We develop methods for detecting precursory signals of earthquakes using atmospheric radon concentration anomalies and GNSS time-series analysis. Our recent work combines statistical anomaly detection techniques — including singular spectrum transformation and Random Forest machine learning — with physical models of radon degassing triggered by tidal loading and crustal strain.

Featured Work

Selected Publications

Key contributions spanning rock experiments, geodynamic modeling, and earthquake forecasting research.

2025
The Brittle‐Plastic Transition in Quartz‐Albite Mixtures: New Insights From Shear Deformation Experiments at Mid‐to‐Lower Crustal Depth Conditions
J. Geophys. Res. Solid Earth
Furukawa, Verberne, Sawa, Nagahama, Takahashi, Plümper & Muto — Shear experiments at simulated mid-to-lower crustal depths reveal microphysical mechanisms controlling the brittle-plastic transition, with grain boundary sliding in nano-grain domains governing crustal strength.
2025
3-D Rheology of Low-Viscosity Zones Around Quaternary Volcanoes from Postseismic Deformation
J. Geophys. Res. Solid Earth
Dhar, Takada & Muto — Three-dimensional inversion of postseismic GNSS data reveals localized low-viscosity zones beneath Quaternary volcanoes of NE Japan.
2019
Coupled Afterslip and Transient Mantle Flow After the 2011 Tohoku Earthquake
Science Advances
Muto, Moore, Barbot, Iinuma, Ohta & Iwamori — Rock-mechanics-based nonlinear rheology modeling reveals that mechanical coupling between afterslip and viscoelastic relaxation controls long-term postseismic evolution.
2024
Detection of Atmospheric Radon Anomalies Using Random Forest Analysis
Scientific Reports
Tsuchiya, Nagahama, Muto, Hirano & Yasuoka — Machine-learning-based anomaly detection in atmospheric radon reveals precursory signals potentially associated with earthquakes.
2016
Reaction-Induced Rheological Weakening Enables Oceanic Subduction
Nature Communications
Hirauchi, Fukushima, Kido, Muto & Okamoto — Deformation experiments demonstrate that metamorphic reactions fundamentally weaken oceanic plates, enabling subduction initiation.
2023
Nonlinear Transient Rheology of Rocks: Decadal GNSS Time Series Analysis
Geophys. Res. Lett.
Dhar & Muto — A function model based on nonlinear transient rock rheology captures the evolving postseismic GNSS signal over a decade after the 2011 Tohoku-Oki earthquake.
Career

Academic Path

2022 – Present
Professor — Graduate School of Science, Tohoku University
Department of Earth Science & International Research Institute of Disaster Science (concurrent)
2019
Visiting Professor — École Normale Supérieure (ENS Paris)
2016 – 2022
Associate Professor — Tohoku University
2008 – 2016
Assistant Professor — Tohoku University
GCOE → Frontier Research Institute → Graduate School of Science
2006 – 2008
JSPS Postdoctoral Fellow (Overseas)
Brown University — with Prof. Jan Tullis & Prof. Greg Hirth
2006
Ph.D. (Science) — Tohoku University
Advisor: Prof. Hiroyuki Nagahama · Tohoku University President's Award
Jun Muto
Jun Muto
Professor, Tohoku University
Alumni

Where Our Graduates Are Now

Our graduates are active in academia, national research institutes, and industry worldwide. Here are some of their stories.

Miho Furukawa 古川 美穂
Ph.D., 2026
Program-Specific Researcher (JSPS PD), Disaster Prevention Research Institute, Kyoto University
Elucidation of micro-deformation mechanisms at the brittle-plastic transition zone (deepest seismogenic layer) of the continental crust; shear experiments using a Griggs-type deformation apparatus and microstructural observation of recovered samples
“武藤研では、実験や分析手法のみならず、試験機の仕組みについても学ぶことができました。また、国際的な視野をもって研究に取り組む環境が整っており、GP-EESプログラムに所属して、のべ６か月間オランダ・ユトレヒト大学で研究を行いました。これらの経験を通じて未知の世界にも飛び込んでいく行動力を身につけることができ、卒業後も新たな環境で挑戦を続けていく際の原動力となっています。”
Furukawa et al. (2025) J. Geophys. Res. doi
Hiroaki Yokoyama 横山 裕晃
Ph.D., 2026
JSPS Postdoctoral Research Fellow (PD), Earth and Planetary Systems Science Program, Hiroshima University
Elucidation of strengthening mechanisms in crustal rocks through deformation microstructure analysis; deformation conditions and history of deformed limestone in the Paleozoic Southern Kitakami Belt
“断層・地殻力学グループでは、野外および変形実験の試料の変形微細解析と変形メカニズムを広く学ぶことができました。博士課程の最終年にはGP-EESプログラムを通じたイギリス・ケンブリッジ大学での研究生活を経験し、日本で得た知見とイギリスで得た知見が相互作用を引き起こしたのを感じました。これは、博士後の研究の道しるべとなっています。”
Yokoyama et al. (2025) Scientific Reports doi
Sambuddha Dhar ダル サムブッダ
Ph.D., 2022
Associate Professor, Osaka Metropolitan University
Numerical simulation analysis of postseismic deformation following the 2011 Tohoku-Oki earthquake
“武藤研では、レオロジーとGNSS観測を用いた地殻変動の数値シミュレーションを学びました。この研究により、世界的に科学的関心の高い2011年東北沖地震後の地表変動パターンを理解することができました。また、この研究を通じて、測地学、地形学、地震学などさまざまな地球科学分野の国内外の専門家と共同研究を行う機会を得ました。現在の准教授職でもその経験が活きています。”
Dhar et al. (2022) Geophys. J. Int. doi
KT
Kiriha Tanaka 田中 桐葉
Ph.D., 2022
Researcher, JAEA (Japan Atomic Energy Agency)
Seismo-electromagnetic phenomena: ESR-based fault dating, surface charge mechanisms, and frictional discharge plasma at fault asperities
“The lab's interdisciplinary approach — bridging geophysics, chemistry, and rock mechanics — gave me a broad perspective that continues to benefit my career at JAEA.”
Tanaka et al. (2022) Phys. Chem. Earth doi
SS
Sando Sawa 澤 燦道
Ph.D., 2022
Assistant Professor, Tohoku University
Experimental seismology: olivine-spinel phase transformation, deep-focus earthquake mechanisms, and rock deformation using Griggs apparatus
“The international environment of the lab — including the GP-EES program and my stay at Bayerisches Geoinstitut — gave me the skills and network to pursue my research career.”
Sawa et al. (2025) J. Geophys. Res. doi
EJ
Eranga Jayawickrama
Ph.D., 2022
Researcher
Rock fracture mechanics: dynamic pulverization under high strain rates using split Hopkinson pressure bar, and X-ray CT analysis of damage evolution in shale
“Working at the Muto Lab allowed me to develop cutting-edge experimental techniques. The supportive environment helped me grow both scientifically and personally.”
Jayawickrama et al. (2023) Rev. Sci. Instrum. doi
Global Network

International Collaborations

Our laboratory maintains active research partnerships with leading institutions across the globe.

International Collaboration Network Map
🇬🇧 University of Cambridge
🇫🇷 ENS Paris · ENS Lyon
🇩🇪 Universität Bremen
🇳🇱 Utrecht University
🇺🇸 Brown · USC · San José State
🇮🇳 IIT Kanpur
🇱🇰 University of Peradeniya
🇰🇷 Andong National University
🇹🇼 National Taiwan Univ. · National Cheng Kung University
🇸🇬 Nanyang Technological University
Opportunities

Join the Lab

Muto Lab members
Muto Lab members — Tohoku University

We welcome motivated researchers and students from around the world who share our passion for understanding Earth's deformation. We offer an international research environment, state-of-the-art experimental facilities (including a Griggs-type deformation apparatus and a split Hopkinson pressure bar), and strong collaborations with institutions worldwide.

Graduate Students

We accept M.Sc. and Ph.D. students through Tohoku University's Graduate School of Science. Research topics span rock deformation experiments, numerical modeling of postseismic deformation, and geochemical monitoring, and are determined through careful consultation. We support both domestic and international students with non-repayable scholarships through various graduate programs and provide guidance for JSPS Research Fellowship applications.

Postdoctoral Researchers

We host JSPS Postdoctoral Fellows and researchers on funded projects. Current projects include numerical modeling of postseismic crustal deformation, earthquake forecasting based on geochemical signals, and synchrotron X-ray operando friction experiments.

Collaborations

We welcome collaborative visits, including sharing of experimental techniques and joint field investigations. We also pursue collaborative research through student exchanges. Our active partnerships include ENS Paris, Bayerisches Geoinstitut (Germany), National Cheng Kung University and National Taiwan University (Taiwan), Nanyang Technological University (Singapore), and many other institutions worldwide.

Contact: muto@tohoku.ac.jp

ORCID: 0000-0001-8493-4051

Full List

Publications

Complete list of 86+ peer-reviewed papers. Search, filter by research theme, and access each paper via DOI link.

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