Volume 1 Issue 1, January 2008

Volume 1 Issue 1

Water is stored within glaciers in linked cavities and at the glacier bed, where it can affect glacier motion. But neither water pressure nor the volume of water stored provides a satisfactory explanation for short-term variations of glacier velocity. Studying Kennicott Glacier, Alaska, Timothy Bartholomaus and colleagues find that short pulses of water, for example due to an outburst flood from a lake upstream, affect glacier velocity the most. The cover image shows Gates Glacier, one of the main tributaries to the Kennicott Glacier.

Cover design by Karen Moore

Letter by Bartholomaus et al.

Editorial

  • Editorial |

    Nature Geoscience launches at the beginning of the United Nations International Year of Planet Earth 2008, subtitled 'Earth sciences for society'. We applaud this theme, but cast our net wider.

Commentary

  • Commentary |

    The Intergovernmental Panel for Climate Change has convinced the public that climate change is real. To tackle it, the panel needs complementary climate services that provide continuous climate information for all regions and the globe.

    • Martin Visbeck

Books and Arts

    No Review

  • Books & Arts |

    'Polar-Palooza', a travelling roadshow celebrating the International Polar Year 2007–2009, highlights the scientific passion of those working on Arctic and Antarctic research, along with their ecological concerns.

    • Ronald Amundson

Research Highlights

News and Views

  • News & Views |

    Modern deep waters form in the Nordic seas when high-salinity surface waters cool and sink. An analysis of Arctic Ocean sediments suggests that throughout the past fifteen million years, brines created during sea-ice formation controlled the sinking of water.

    • Ellen Martin
  • News & Views |

    India and Arabia collide with Eurasia at slightly different velocities. Detailed mapping of the Arabian Sea suggests that this motion started between 3 and 8 million years ago, possibly with a transfer of an Arabian plate wedge to the Indian plate.

    • Charles DeMets
  • News & Views |

    The atmosphere's lowermost 10 km have long been assumed to be almost solely responsible for weather and climate on Earth. Emerging evidence points to the layer above as an important influence on surface winds and temperatures on seasonal to decadal timescales.

    • Tiffany A. Shaw
    •  & Theodore G. Shepherd
  • News & Views |

    The relationship between carbon dioxide and climate over millions of years has been a source of controversy. Fossilized liverwort leaves can help illuminate both temperature and atmospheric carbon dioxide levels from 200 to 60 million years ago.

    • Klaus Wallmann
  • News & Views |

    In aerosol hot spots around the globe, solar radiation is dimmed down on its way to the Earth's surface. The resulting surface cooling turns out to be almost in balance with heating of the atmosphere due to black carbon.

    • John Seinfeld
  • News & Views |

    Neither recycled oceanic crust nor sediments alone can explain the composition of ocean-island basalts, but how about a mixture of the two? Recent modelling using the isotopes of hafnium and neodymium appears to support this contention.

    • Terry Plank
    •  & Peter E. van Keken
  • News & Views |

    From about 470 million years ago, the Middle Ordovician period witnessed a rapid increase in biodiversity. This explosion in numbers of species is almost perfectly contemporaneous with an increased frequency of meteorite impacts.

    • Florentin Paris

Progress Article

  • Progress Article |

    The tropical belt has been widening over past decades — as estimated from a number of independent lines of evidence — shifting the dry subtropical climate zones polewards around the world.

    • Dian J. Seidel
    • , Qiang Fu
    • , William J. Randel
    •  & Thomas J. Reichler

Review

  • Review Article |

    Emerging evidence for threefold higher heat flow across the core–mantle boundary prompts a re-evaluation of the role of thermal plumes in geodynamics and the thermal history of the Earth's core and lower mantle.

    • Thorne Lay
    • , John Hernlund
    •  & Bruce A. Buffett

Letters

  • Letter |

    The speed of a glacier is affected most by sudden jumps in the water supply to the glacier, but it goes back to previous levels if high water inputs are sustained because the glacier's plumbing system adjusts.

    • Timothy C. Bartholomaus
    • , Robert S. Anderson
    •  & Suzanne P. Anderson
  • Letter |

    Sea level during the last interglacial stood at least 4 m higher than at present, with evidence of short-term fluctuations of up to 10 m. A new continuous sea level record from the Red Sea and coral ages suggest that during these fluctuations, sea level changes were on the order of 1.6 m per century.

    • E. J. Rohling
    • , K. Grant
    • , Ch. Hemleben
    • , M. Siddall
    • , B. A. A. Hoogakker
    • , M. Bolshaw
    •  & M. Kucera
  • Letter |

    Carbon isotopes of fossil plants and model simulations suggest that atmospheric carbon dioxide levels were variable during the period 200 to 60 million years ago. The large decreases in the partial pressure of CO2 coincide with glaciations, providing evidence against climate–CO2 decoupling during the Mesozoic.

    • Benjamin J. Fletcher
    • , Stuart J. Brentnall
    • , Clive W. Anderson
    • , Robert A. Berner
    •  & David J. Beerling
  • Letter |

    The Great Ordovician Biodiversification Event coincides ~470 million years ago with the break-up of a large asteroid and the resultant frequent bombardment of Earth with asteroid fragments.

    • Birger Schmitz
    • , David A. T. Harper
    • , Bernhard Peucker-Ehrenbrink
    • , Svend Stouge
    • , Carl Alwmark
    • , Anders Cronholm
    • , Stig M. Bergström
    • , Mario Tassinari
    •  & Wang Xiaofeng
  • Letter |

    Multibeam mapping of the northwestern Indian Ocean seafloor provides clear evidence of dextral strike-slip motion along the Owen fracture zone and helps constrain the nature of deformation as well as the rate of slip along this little-studied plate boundary.

    • Marc Fournier
    • , Nicolas Chamot-Rooke
    • , Carole Petit
    • , Olivier Fabbri
    • , Philippe Huchon
    • , Bertrand Maillot
    •  & Claude Lepvrier
  • Letter |

    Clustering of earthquakes at various spatial scales is the result of a heterogeneous distribution of stresses, and – at least for intermediate-magnitude earthquakes – areas that are quiet at present are likely to remain so in the future.

    • Tom Parsons

Article

  • Article |

    Over the past 15 million years, Arctic Ocean circulation has exhibited two distinct modes: during the interglacial periods of the past two million years, including the present, Arctic intermediate water was mainly derived from North Atlantic inflow. By contrast, between 15 and 2 million years ago, and during glacial periods thereafter, brine formation on the Eurasian shelves contributed substantially to Arctic intermediate water.

    • Brian A. Haley
    • , Martin Frank
    • , Robert F. Spielhagen
    •  & Anton Eisenhauer

Backstory

  • Backstory |

    Tim Bartholomaus and Suzanne and Bob Anderson hauled 25 kilograms of equipment over 25 kilometres in 25 hours to get a handle on glacier flow — without breaking the bank.

  • Backstory |

    Using sophisticated multibeam imaging equipment aboard a French Navy vessel, Marc Fournier and colleagues mapped the structure of the enigmatic Owen fracture zone underneath the Arabian Sea.

  • Backstory |

    Kate Moran and Jan Backman took an ice-hardened drillship, two icebreakers and two helicopters to the high Arctic to recover many million-year-old sediments from the Lomonosov Ridge.