Geodynamics articles within Nature

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  • Letter |

    Ancient shorelines on Mars must have formed before and during the emplacement of the Tharsis volcanic province, instead of afterwards as previously assumed, suggesting that oceans on Mars formed early.

    • Robert I. Citron
    • , Michael Manga
    •  & Douglas J. Hemingway

  • Article |

    An estimate of Earth’s deep-mantle buoyancy is derived from GPS-based measurements of body tide deformation and shown to be dominated by dense material possibly related to subducted oceanic plates or primordial rock.

    • Harriet C. P. Lau
    • , Jerry X. Mitrovica
    •  & David Al-Attar

  • Letter |

    The pyrite-type high-pressure form of FeOOH is predicted from first principles, and found experimentally to be stable under the conditions at the base of the mantle, with implications for transport of water within Earth’s deep interior.

    • Masayuki Nishi
    • , Yasuhiro Kuwayama
    •  & Taku Tsuchiya

  • Letter |

    Phase equilibria modelling of rocks from Western Australia confirms that the ancient continental crust could have formed by multistage melting of basaltic ‘parents’ along high geothermal gradients—a process incompatible with modern-style subduction.

    • Tim E. Johnson
    • , Michael Brown
    •  & R. Hugh Smithies

  • Letter |

    Analysis of helium isotope ratios in volcanic hotspot lavas suggests that hotter, more buoyant plumes upwelling from the deep mantle entrain high-3He/4He material, unlike cooler, less buoyant plumes, implying the existence of a dense, relatively undisturbed primordial reservoir in the deep mantle.

    • M. G. Jackson
    • , J. G. Konter
    •  & T.W. Becker

  • Letter |

    Modelling suggests that the icy region on Pluto known as Sputnik Planitia formed shortly after Charon did and has since been stable, with its latitude corresponding to a minimum in annual solar illumination and its longitude determined by tidal forces from Charon.

    • Douglas P. Hamilton
    • , S. A. Stern
    •  & H. A. Weaver

  • Letter |

    Neodynium isotope data reveal that the Earth is enriched in material from red giant stars relative to its presumed meteoritic building blocks, refuting models of a hidden reservoir of 142Nd-depleted material or a ‘super-chondritic’ Earth.

    • C. Burkhardt
    • , L. E. Borg
    •  & T. Kleine

  • Letter |

    Trace-element analyses of olivine phenocrysts and diamond inclusions indicate that carbonatite-metasomatized subcontinental mantle may be the source of the HIMU mantle end-member, as opposed to recycled basaltic oceanic crust.

    • Yaakov Weiss
    • , Cornelia Class
    •  & Takeshi Hanyu

  • Letter |

    By applying a new geotectonic analysis technique to revised global plate reconstructions, rifted margins are shown to feature an initial slow rift phase followed by an abrupt increase of plate divergence prior to breakup.

    • Sascha Brune
    • , Simon E. Williams
    •  & R. Dietmar Müller

  • Letter |

    Experiments show that magnesium oxide can dissolve in core-forming metallic melts at very high temperatures; core formation models suggest that a giant impact during Earth’s accretion could have contributed large amounts of magnesium to the early core, the subsequent exsolution of which would have generated enough gravitational energy to power an early geodynamo and produce an ancient magnetic field.

    • James Badro
    • , Julien Siebert
    •  & Francis Nimmo

  • Letter |

    Computer models of mantle convection with plate-like behaviour are used to demonstrate that the size–frequency distribution of tectonic plates on Earth is controlled by subduction geometry—the spacing between subducting slabs controls the layout of large plates, and the stresses caused by the bending of trenches break plates into smaller fragments.

    • Claire Mallard
    • , Nicolas Coltice
    •  & Paul J. Tackley

  • Letter |

    A parameterized convection model and observations of the puzzling polygons of the Sputnik Planum region of Pluto are used to compute the Rayleigh number of its nitrogen ice and show that it is vigorously convecting, kilometres thick and about a million years old.

    • A. J. Trowbridge
    • , H. J. Melosh
    •  & A. M. Freed

  • Letter |

    The volatile-ice-filled basin informally named Sputnik Planum is central to Pluto’s geological activity; this ice layer is organized into cells or polygons, and it is now shown that convective overturn in a several-kilometre-thick layer of solid nitrogen can explain both the presence of the cells and their great width.

    • William B. McKinnon
    • , Francis Nimmo
    •  & K. E. Smith

  • Letter |

    A light-weight, low-cost microelectromechanical system gravimeter is presented with sensitivity and stability high enough to measure the elastic deformation of the Earth’s crust as a result of tidal forces, enabling many applications.

    • R. P. Middlemiss
    • , A. Samarelli
    •  & G. D. Hammond

  • Letter |

    Polar hydrogen deposits on the Moon provide evidence that its spin axis has shifted; analysis of the locations of these deposits and of the lunar figure suggests that the shift occurred as a result of changes in the Moon’s moments of inertia caused by a low-density thermal anomaly beneath the Procellarum region.

    • M. A. Siegler
    • , R. S. Miller
    •  & M. J. Poston

  • Letter |

    By calculating the rotational figure of Mars and its surface topography before the Tharsis volcanic region caused true polar wander, it is shown that Tharsis formed during the Noachian and Hesperian periods at about the same time as the valley networks; early Mars climate simulations suggest icy precipitation in a latitudinal band in the southern hemisphere.

    • Sylvain Bouley
    • , David Baratoux
    •  & Francois Costard

  • Letter |

    Deformation experiments on lawsonite reveal that unstable fault slip occurs during dehydration reactions with continuous acoustic emission signals; this indicates the potential for unstable frictional sliding in natural lawsonite layers, which could possibly be the source of intermediate-depth earthquakes in cold subduction zones.

    • Keishi Okazaki
    •  & Greg Hirth

  • Letter |

    The thermal conductivity of iron is now known to be much larger than had been thought, implying that thermal convection and radiogenic heating would not have been enough to sustain the Earth’s geodynamo; here it is shown that the precipitation of magnesium-bearing minerals from the core could have served as the required power source.

    • Joseph G. O’Rourke
    •  & David J. Stevenson

  • Letter |

    In metre-sized rock specimens, rock friction starts to decrease at a much smaller work rate than in centimetre-sized rock specimens, thus demonstrating that rock friction is scale-dependent.

    • Futoshi Yamashita
    • , Eiichi Fukuyama
    •  & Hironori Kawakata

  • Letter |

    A whole-mantle seismic imaging technique, combining accurate wavefield computations with information contained in whole seismic waveforms, is used to reveal the presence of broad conduits beneath many of Earth’s surface hotspots, supporting the idea that these conduits are the source of hotspot volcanoes.

    • Scott W. French
    •  & Barbara Romanowicz

  • Letter |

    Results from mantle flow models reveal a relationship between seismicity away from the plate boundary in the western United States and the rate change of the vertical normal stress from mantle flow, showing that mantle flow plays an important part in shaping topography, tectonics and seismic hazard within such intraplate settings.

    • Thorsten W. Becker
    • , Anthony R. Lowry
    •  & Chunquan Yu

  • Letter |

    Flat-slab subduction is often proposed to cause deformation of continental crust far from plate boundaries as well as unusual patterns of volcanism; a study of the largest-known flat slab, located in Peru, now shows that the ridge is necessary for the formation and longevity of the flat slab, whereas other contributing factors such as trench retreat and suction alone will not suffice.

    • Sanja Knezevic Antonijevic
    • , Lara S. Wagner
    •  & Cristobal Condori

  • Letter |

    Observations of the south pole of the Saturnian moon Enceladus revealed large rifts in the terrain that were found to be the sources of the observed jets of water vapour; now it is shown that much of the eruptive activity can be explained by broad, curtain-like eruptions, many of which were probably misinterpreted previously as discrete jets.

    • Joseph N. Spitale
    • , Terry A. Hurford
    •  & Symeon S. Platts

  • Letter |

    Based on first-principles resistivity calculations, it was recently concluded that the thermal conductivity of iron in Earth’s core was too high to sustain thermal convection, thus invalidating such geodynamo models; new calculations including electron correlations find that electron–electron scattering is comparable to the electron–phonon scattering at high temperatures in iron, doubling the expected resistivity, and reviving conventional geodynamo models.

    • Peng Zhang
    • , R. E. Cohen
    •  & K. Haule

  • Letter |

    Examination of the global uranium cycle — whereby uranium from the Earth’s crust is first transported to the oceans and then returned, by subduction, to the mantle — shows that the subducted uranium is isotopically distinct from the Earth as a whole and that this signature has been stirred throughout upper mantle, arguably within the past 600 million years.

    • Morten B. Andersen
    • , Tim Elliott
    •  & Katherine A. Kelley

  • Letter |

    Seismicity and ground deformation measurements show how a recent segmented dyke intrusion in the Bárðarbunga volcanic system in Iceland grew laterally for 45 kilometres over 14 days; dyke opening and seismicity were focused at the most distal segment, where lateral dyke growth with segment barrier breaking by pressure build-up occurred.

    • Freysteinn Sigmundsson
    • , Andrew Hooper
    •  & Eva P. S. Eibl

  • Letter |

    Seismic images of the subducted Atlantic slab under northeastern South America and the Alboran slab beneath the Gibraltar arc region show that subducting oceanic plates viscously entrain and remove the bottom of the continental thermal boundary layer from adjacent continental margins, driving surface tectonics and pre-conditioning the margins for further deformation.

    • A. Levander
    • , M. J. Bezada
    •  & M. S. Miller

  • Letter |

    The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth’s interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

    • Patrice F. Rey
    • , Nicolas Coltice
    •  & Nicolas Flament

  • Letter |

    Seafloor Global Positioning System observations immediately after the great 2011 Tohoku-oki earthquake provide unambiguous evidence for the dominant role of viscoelastic relaxation in short-term postseismic deformation, rather than just afterslip on the fault as is commonly assumed.

    • Tianhaozhe Sun
    • , Kelin Wang
    •  & Yan Hu

  • Letter |

    Three-dimensional numerical models of the interaction of a mantle plume with a rheologically realistic lithosphere predict complex surface evolution very different from the smooth, radially symmetric patterns usually assumed to be the signature of a mantle upwelling, with strongly asymmetric small-scale three-dimensional features such as rifts and linear fault structures.

    • Evgueni Burov
    •  & Taras Gerya

  • Letter |

    Analysis of the Moon's topography reveals that when its largest basins are removed, the lunar shape is consistent with processes controlled by early Earth tides, and implies a reorientation of the Moon's principal shape axes.

    • Ian Garrick-Bethell
    • , Viranga Perera
    •  & Maria T. Zuber

  • Letter |

    High-resolution three-dimensional simulations of hydrothermal flow beneath fast-spreading ridges predict two interacting flow components — shallow on-axis flow and deeper off-axis flow — that merge to feed axial vent sites, reconciling previously incompatible models favouring only one flow component.

    • Jörg Hasenclever
    • , Sonja Theissen-Krah
    •  & Colin W. Devey

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