Global Centroid Moment Tensor Project

Global Centroid Moment Tensor Project
Name	Global Centroid Moment Tensor Project
Abbrev	GCMT
Formation	1982
Type	Research project
Headquarters	Princeton, New Jersey
Parent organization	Lamont–Doherty Earth Observatory / Columbia University

Contents

Global Centroid Moment Tensor Project The Global Centroid Moment Tensor Project provides a global catalog of seismic centroid moment tensors for earthquakes, offering moment magnitude, focal mechanisms, and centroid depths that are widely used in seismology, geophysics, and tectonics. The project’s catalog and analysis tools inform studies by institutions such as United States Geological Survey, Lamont–Doherty Earth Observatory, Institut de Physique du Globe de Paris, California Institute of Technology, and Massachusetts Institute of Technology. Data from the project are integrated by operational centers including International Seismological Centre, European-Mediterranean Seismological Centre, Japan Meteorological Agency, and research networks linked to IRIS (organization), Global Seismographic Network, and regional arrays.

Overview

The project compiles centroid moment tensors that describe earthquake source processes through moment magnitude, double-couple percentage, centroid location, and focal mechanism parameters used by researchers at Princeton University, Harvard University, Stanford University, University of Washington, and Scripps Institution of Oceanography. Its outputs underpin analyses in studies of subduction zones near Japan Trench, Cascadia subduction zone, and Peru-Chile Trench, as well as intraplate events in regions such as New Madrid Seismic Zone, Kaikōura, and Hawaii. Collaborators and users include agencies like National Oceanic and Atmospheric Administration, Defense Advanced Research Projects Agency, and academic programs funded by National Science Foundation and European Research Council.

Seismic waveform data are sourced from global networks including Global Seismographic Network, GEOSCOPE, GEOSCOPE Observatory, Canadian National Seismograph Network, Australian Seismological Centre, and regional arrays run by Korea Meteorological Administration and China Earthquake Administration. The methodology builds on moment tensor inversion techniques developed by researchers at Massachusetts Institute of Technology, California Institute of Technology, and Institut de Physique du Globe de Paris using Green’s functions, velocity models like PREM, IASP91, and regional 3-D models from USArray. Processing pipelines reference work by authors affiliated with Lamont–Doherty Earth Observatory, Seismological Society of America, American Geophysical Union, and computational methods taught in courses at Columbia University and University of California, Berkeley.

The catalog provides standardized parameters—centroid depth, moment magnitude (Mw), strike, dip, rake, seismic moment tensor components—organized for query and download by researchers at Princeton University, University of Oxford, ETH Zurich, National Taiwan University, and Peking University. It interfaces with visualization and analysis tools from ObsPy, SeisComP, SAC (file format), and platforms promoted by IRIS (organization) and International Seismological Centre. Metadata conform to conventions used by UNAVCO, Global Earthquake Model, and digital repositories at Zenodo and institutional archives at Lamont–Doherty Earth Observatory.

GCMT catalog products support earthquake source studies in contexts such as faulting in the San Andreas Fault, stress transfer following the 2004 Indian Ocean earthquake and tsunami, tsunami source inversion used after the 2011 Tōhoku earthquake and tsunami, and seismic hazard assessment for regions like Los Angeles, Tokyo, and Istanbul. The dataset has informed research by groups at Scripps Institution of Oceanography, ETH Zurich, University of Cambridge, Australian National University, and National Research Council (Italy), contributing to publications in journals such as Nature, Science, Journal of Geophysical Research, and Geophysical Journal International. It is used in multidisciplinary studies connecting to GPS (satellite navigation), InSAR, and paleoseismology investigations near sites like San Andreas Fault Observatory at Depth.

Quality control procedures rely on cross-validation with catalogs from United States Geological Survey, International Seismological Centre, European-Mediterranean Seismological Centre, and regional agencies such as Meteorological Service of Canada and Geoscience Australia. Validation methods incorporate synthetic tests, bootstrap analyses, comparisons to point-source inversions by groups at Caltech, and waveform misfit metrics applied in software from IRIS (organization) and community toolkits developed at Stanford University and University of Southern California. Quality flags and uncertainty estimates follow community standards discussed in meetings of the Seismological Society of America and American Geophysical Union.

The project originated in the early 1980s with foundational work by researchers associated with Lamont–Doherty Earth Observatory and collaborations involving Harvard University and Caltech. Over time it evolved through partnerships with IRIS (organization), USGS, and international research centers such as GFZ German Research Centre for Geosciences, INGV, and NCEDC. Governance includes scientific steering from academic groups at Columbia University and operational support from institutions like Princeton University and Lamont–Doherty Earth Observatory, with contributions from visiting scientists from Japan Agency for Marine-Earth Science and Technology, Korea Institute of Geoscience and Mineral Resources, and Chinese Academy of Sciences.

Data access is provided via downloadable catalog files and query services used by researchers at IRIS (organization), International Seismological Centre, USGS, UNAVCO, and university groups at MIT and University of California, Santa Cruz. Analysis and visualization workflows commonly employ ObsPy, SAC (file format), GMT (software), and GIS platforms taught in courses at Columbia University and ETH Zurich. The catalog supports integration into operational products from European-Mediterranean Seismological Centre and tsunami warning centers such as Pacific Tsunami Warning Center for rapid characterization of large events.