Volume 15

  • No. 7 July 2022

    Vulnerable mountain infrastructure

    Climate change is exacerbating geohazards in High Mountain Asia that pose a growing risk to hydropower and water infrastructure across the region. Improved monitoring and forecasting of cascading hazards and sustainable sediment management solutions are needed to inform climate change-resilient hydropower. The image shows an expanding moraine-dammed glacial lake in the Himalaya.

    See Li et al.

  • No. 6 June 2022

    Bennu’s active surface

    The OSIRIS REx spacecraft’s observations of the rubble-pile asteroid Bennu reveal a weak and active surface undergoing rapid evolution. Bennu’s rugged geology — as imaged by the MapCam instrument onboard the spacecraft on 16 December 2018 — shows a surface littered with boulders, which cast long shadows owing to the high phase angle. Near the horizon, two large bowl-shaped craters can be seen: Ohnivak (~40 m diameter) and Alicanto (~60 m diameter).

    see Bierhaus et al. , Perry et al. , Delbo et al. and News & Views by Arakawa

  • No. 5 May 2022

    Precursors to eruption

    Ingression of magmatic gas into a geothermal aquifer generated cyclical deformation and primed the system for the 2021 Fagradalsfjall eruption, Iceland, according to a catalogue of 39,500 precursory earthquakes combined with a poroelastic model. The image, taken on the sunny evening of May 8th 2021, shows new black lava covering the bottom of the Geldingadalur valley releasing sulfury gasses while the crater emits volcanic gasses to the atmosphere.

    See Flóvenz et al.

  • No. 4 April 2022

    Oxidation by subducting metasediments

    Metasedimentary rocks atop the subducting slab oxidize ascending slab-derived dehydration fluids by removal of reduced species, according to petrological analysis of subduction complex metasedimentary rocks and reactive transport modelling. The image of a polished rock sample from Crete, Greece, shows subducted metamorphosed bauxite preserving a relic pisolitic structure that formed during surficial oxidative weathering.

    See Ague  et al.

  • No. 3 March 2022

    From dust to clouds

    Cirrus cloud formation in the northern hemisphere is primarily triggered by mineral dust, according to global-scale dust observations and a cirrus formation model. In the image dust aerosol reddens the sunrise as the DC-8 aircraft prepares to sample the remote atmosphere during the NASA Atmospheric Tomography mission.

    See Froyd et al.

  • No. 2 February 2022

    Legacies of agricultural nitrogen

    Mitigation efforts to curb agricultural nitrogen have been largely unsuccessful, but managing previously overlooked nitrogen legacies of landscapes could improve water quality. The image shows a late-summer phytoplankton bloom swirling in the Baltic Sea between the Swedish islands of Öland and Gotland. Such blooms have intensified in the last few decades. The image was taken in August 2020 using the Operation Land Imager instrument on Landsat 8.

    See Basu et al.

  • No. 1 January 2022

    Tropical cyclones on the move

    Hurricanes and typhoons are tracking further poleward due to the effects of climate change, according to a synthesis of numerical modelling results, observations, and paleoclimate records. This image illustrates the multi-scalar complexity of tropical cyclone processes that are poorly resolved in modern climate models. Five days after this convective structure was imaged, it became the category-5 Typhoon Goni.

    See Studholme et al.