Deformation cycles of subduction earthquakes in a viscoelastic Earth

• Published in: Nature (London) 2012-04, Vol.484 (7394), p.327-332
• Main Authors: Wang, Kelin, Hu, Yan, He, Jiangheng
• Format: Article
• Language: English
• Subjects: 704/2151/213; Comparative studies; Earth; Earth sciences; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Environmental aspects; Exact sciences and technology; Geodesy; Geodetics; Global Positioning System; Humanities and Social Sciences; Internal geophysics; multidisciplinary; Plate tectonics; review-article; Science; Science (multidisciplinary); Seismic activity; Solid-earth geophysics, tectonophysics, gravimetry; Tectonics. Structural geology. Plate tectonics; Tsunamis; United States
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature11032

Subduction zones produce the largest earthquakes. Over the past two decades, space geodesy has revolutionized our view of crustal deformation between consecutive earthquakes. The short time span of modern measurements necessitates comparative studies of subduction zones that are at different stages of the deformation cycle. Piecing together geodetic ‘snapshots’ from different subduction zones leads to a unifying picture in which the deformation is controlled by both the short-term (years) and long-term (decades and centuries) viscous behaviour of the mantle. Traditional views based on elastic models, such as coseismic deformation being a mirror image of interseismic deformation, are being thoroughly revised. ‘Snapshots’ of subduction zones using space geodesy reveal that the viscous behaviour of the mantle controls crustal deformation, requiring the revision of traditional ‘elastic’ models for earthquake risk assessment. Modelling the earthquake cycle Space geodesy — the use of satellites to monitor Earth — has revolutionized our view of crustal deformation between consecutive earthquakes. However, the brevity of such measurements means that studies must be done by comparing multiple subduction zones at different stages of the earthquake cycle. By piecing together geodetic 'snapshots' from the Sumatra, Chile and Cascadia subduction zones, this Review presents a unifying picture in which deformation is controlled by the viscous behaviour of the mantle in both the short term (years) and the long term (decades to centuries).