The Law of the Sea - p153

doi:10.1038/ngeo464

In 2008 ocean iron fertilization was regulated under two sets of international legislation. However, unclear definitions have led to the suspension of legitimate research.

Full Text - The Law of the Sea | PDF (132 KB) - The Law of the Sea

Near-real-time aftershock hazard maps - pp154 - 155

John McCloskey & Suleyman S. Nalbant

doi:10.1038/ngeo449

Full Text - Near-real-time aftershock hazard maps | PDF (325 KB) - Near-real-time aftershock hazard maps

Open access? - p155

Peter Suber

doi:10.1038/ngeo450

Full Text - Open access? | PDF (110 KB) - Open access?

Open access? - p155

Global Earthquake Model founders

doi:10.1038/ngeo466

Full Text - Open access? | PDF (110 KB) - Open access?

Kick-starting ancient warming - pp156 - 159

E. G. Nisbet, S. M. Jones, J. Maclennan, G. Eagles, J. Moed, N. Warwick, S. Bekki, P. Braesicke, J. A. Pyle & C. M. R. Fowler

doi:10.1038/ngeo454

Rapid global warming marked the boundary between the Palaeocene and Eocene periods 55.6 million years ago, but how the temperature rise was initiated remains elusive. A catastrophic release of greenhouse gases from the Kilda basin could have served as a trigger.

Full Text - Kick-starting ancient warming | PDF (431 KB) - Kick-starting ancient warming | Supplementary information

A marine voyage of discovery - p160

Leslie R. Sautter reviews Chasing Science at Sea by Ellen Prager

doi:10.1038/ngeo453

Full Text - A marine voyage of discovery | PDF (126 KB) - A marine voyage of discovery

Our choice from the recent literature - p161

doi:10.1038/ngeo463

Full Text - Our choice from the recent literature | PDF (186 KB) - Our choice from the recent literature

Climate science: Patchy peat - pp163 - 164

Torben R. Christensen

doi:10.1038/ngeo455

Nutrient-rich tropical and agricultural soils release vast quantities of the highly potent greenhouse gas nitrous oxide. New measurements show that vegetation-free patches of tundra in subarctic Europe can also emit large quantities of this gas.

Full Text - Climate sciencePatchy peat | PDF (362 KB) - Climate sciencePatchy peat

Subject Category: Climate science

See also: Letter by Repo et al.

Carbon capture: Made to measure - p164

Anna Armstrong

doi:10.1038/ngeo461

Full Text - Carbon captureMade to measure | PDF (194 KB) - Carbon captureMade to measure

Hydrology: Forming valleys from below - pp165 - 166

Alan D. Howard

doi:10.1038/ngeo447

Surface water is known to shape the formation and growth of valleys and channels. However, in some geologic settings, groundwater seeping upwards is important for the development of channel networks.

Full Text - HydrologyForming valleys from below | PDF (304 KB) - HydrologyForming valleys from below

Subject Category: Hydrology, hydrogeology and limnology

See also: Letter by Abrams et al.

Geomorphology: Crater or not? - p166

Ninad Bondre

doi:10.1038/ngeo452

Full Text - GeomorphologyCrater or not? | PDF (149 KB) - GeomorphologyCrater or not?

Atmospheric science: Smoke above clouds - pp167 - 168

Lorraine A. Remer

doi:10.1038/ngeo456

Aerosols in the atmosphere alter the radiative balance of the Earth by reflecting or absorbing solar radiation. Space-borne measurements of clouds and aerosols advected over the southeastern Atlantic Ocean indicate that the greater the cloud cover below the aerosols, the more likely the aerosols are to heat the planet.

Full Text - Atmospheric scienceSmoke above clouds | PDF (230 KB) - Atmospheric scienceSmoke above clouds

Subject Category: Atmospheric science

See also: Letter by Chand et al.

Mantle mineralogy: Deep heat - p168

Ninad Bondre

doi:10.1038/ngeo451

Full Text - Mantle mineralogyDeep heat | PDF (114 KB) - Mantle mineralogyDeep heat

Planetary science: Ancient equatorial ice on Mars? - pp169 - 170

Brian Hynek

doi:10.1038/ngeo448

NASA's Opportunity rover found enigmatic sulphate deposits at Meridiani Planum on Mars. A proposal that the deposits are sublimation leftovers of large ice-fields, similar in scale to those at the present-day polar caps, adds to the existing hypotheses.

Full Text - Planetary scienceAncient equatorial ice on Mars? | PDF (189 KB) - Planetary scienceAncient equatorial ice on Mars?

Subject Category: Planetary science

See also: Article by Niles & Michalski

Palaeoclimate: Atmospheric carbon footprints? - pp170 - 172

Edward J. Brook

doi:10.1038/ngeo446

According to one controversial idea, increases in atmospheric greenhouse-gas concentrations due to human activities can be detected as early as several thousand years ago. Eight years after the publication of this hypothesis, controversy continues.

Full Text - PalaeoclimateAtmospheric carbon footprints? | PDF (117 KB) - PalaeoclimateAtmospheric carbon footprints?

Subject Category: Palaeoclimate and palaeoceanography

A heat-induced molecular signature in marine dissolved organic matter - pp175 - 179

Thorsten Dittmar & Jiyoung Paeng

doi:10.1038/ngeo440

Marine dissolved oragnic matter contains roughly as much organic carbon as all living biota on land and in the oceans combined. New techniques in analytical chemistry show that a significant portion of this material has undergone thermal alteration, either on land or in sediments deep below the sea floor.

Abstract - A heat-induced molecular signature in marine dissolved organic matter | Full Text - A heat-induced molecular signature in marine dissolved organic matter | PDF (465 KB) - A heat-induced molecular signature in marine dissolved organic matter

Subject Categories: Biogeochemistry | Oceanography

Satellite-derived direct radiative effect of aerosols dependent on cloud cover - pp181 - 184

D. Chand, R. Wood, T. L. Anderson, S. K. Satheesh & R. J. Charlson

doi:10.1038/ngeo437

Aerosols from biomass burning can alter the radiative energy balance of the Earth by reflecting or absorbing solar radiation. Satellite measurements indicate that the amount of energy absorbed by aerosols at the top of the atmosphere increases with underlying cloud coverage.

First Paragraph - Satellite-derived direct radiative effect of aerosols dependent on cloud cover | Full Text - Satellite-derived direct radiative effect of aerosols dependent on cloud cover | PDF (2,466 KB) - Satellite-derived direct radiative effect of aerosols dependent on cloud cover | Supplementary information

Subject Categories: Atmospheric science | Climate science

See also: News and Views by Remer

Human amplification of drought-induced biomass burning in Indonesia since 1960 - pp185 - 188

Robert D. Field, Guido R. van der Werf & Samuel S. P. Shen

doi:10.1038/ngeo443

Under drought conditions, biomass burning in Indonesia is a disproportionate contributor to the global carbon dioxide emissions from such events. An analysis of Indonesian records of large fires shows that their occurrence is linked to land use and population dynamics, and that the Indian Ocean climate and El Niño both have an equally important influence.

First Paragraph - Human amplification of drought-induced biomass burning in Indonesia since 1960 | Full Text - Human amplification of drought-induced biomass burning in Indonesia since 1960 | PDF (792 KB) - Human amplification of drought-induced biomass burning in Indonesia since 1960 | Supplementary information

Subject Categories: Climate science | Ecology | Hydrology, hydrogeology and limnology

See also: related Backstory

Large N₂O emissions from cryoturbated peat soil in tundra - pp189 - 192

Maija E. Repo, Sanna Susiluoto, Saara E. Lind, Simo Jokinen, Vladimir Elsakov, Christina Biasi, Tarmo Virtanen & Pertti J. Martikainen

doi:10.1038/ngeo434

Nitrous oxide is a potent greenhouse gas whose concentration is increasing in the atmosphere; the highest emissions have been observed from agricultural and tropical soils. Now, measurements in subarctic East European tundra show that bare surfaces on permafrost peatlands, known as peat circles, release large quantities of nitrous oxide.

First Paragraph - Large N: 2: O emissions from cryoturbated peat soil in tundra | Full Text - Large N2O emissions from cryoturbated peat soil in tundra | PDF (1,201 KB) - Large N2O emissions from cryoturbated peat soil in tundra | Supplementary information

Subject Categories: Biogeochemistry | Climate science

See also: News and Views by Christensen

Growth laws for channel networks incised by groundwater flow - pp193 - 196

Daniel M. Abrams, Alexander E. Lobkovsky, Alexander P. Petroff, Kyle M. Straub, Brandon McElroy, David C. Mohrig, Arshad Kudrolli & Daniel H. Rothman

doi:10.1038/ngeo432

Groundwater seepage is expected to affect channel features, but its role remains controversial. Two linear response relationships that describe channel evolution from groundwater flux are sufficient to characterize seepage-driven channel networks, linking the dynamics of channel growth to channel morphology.

First Paragraph - Growth laws for channel networks incised by groundwater flow | Full Text - Growth laws for channel networks incised by groundwater flow | PDF (9,962 KB) - Growth laws for channel networks incised by groundwater flow | Supplementary information

Subject Category: Hydrology, hydrogeology and limnology

See also: related Backstory | News and Views by Howard

Preservation of iron(II) by carbon-rich matrices in a hydrothermal plume - pp197 - 201

Brandy M. Toner, Sirine C. Fakra, Steven J. Manganini, Cara M. Santelli, Matthew A. Marcus, James W. Moffett, Olivier Rouxel, Christopher R. German & Katrina J. Edwards

doi:10.1038/ngeo433

Hydrothermal vents release significant quantities of dissolved iron into the oceans. Spectromicroscopic examination of a hydrothermal plume suggests that carbon-rich matrices protect this iron from oxidation and precipitation.

First Paragraph - Preservation of iron(: II: ) by carbon-rich matrices in a hydrothermal plume | Full Text - Preservation of iron(II) by carbon-rich matrices in a hydrothermal plume | PDF (1,054 KB) - Preservation of iron(II) by carbon-rich matrices in a hydrothermal plume | Supplementary information

Subject Category: Biogeochemistry

Rapid oceanic and atmospheric changes during the Younger Dryas cold period - pp202 - 205

Jostein Bakke, Øyvind Lie, Einar Heegaard, Trond Dokken, Gerald H. Haug, Hilary H. Birks, Peter Dulski & Trygve Nilsen

doi:10.1038/ngeo439

The Younger Dryas event was a brief return to cold conditions before the onset of interglacial warmth. An analysis of sediment records from Lake Kråkenes in Norway and the Nordic Seas shows that during the late Younger Dryas, Northern Europe underwent rapidly oscillating climate conditions, possibly related to the break-up of Nordic sea-ice.

First Paragraph - Rapid oceanic and atmospheric changes during the Younger Dryas cold period | Full Text - Rapid oceanic and atmospheric changes during the Younger Dryas cold period | PDF (1,314 KB) - Rapid oceanic and atmospheric changes during the Younger Dryas cold period | Supplementary information

Subject Category: Palaeoclimate and palaeoceanography

Glacial terminations as southern warmings without northern control - pp206 - 209

E. W. Wolff, H. Fischer & R. Röthlisberger

doi:10.1038/ngeo442

The timing and mechanisms of the transition from a glacial to an interglacial state are controversial. An analysis of Antarctic ice-core records indicates that glacial terminations may begin as millennial-scale warmings in the southern hemisphere that, unlike previous events, are not reversed by abrupt warming in the northern hemisphere.

First Paragraph - Glacial terminations as southern warmings without northern control | Full Text - Glacial terminations as southern warmings without northern control | PDF (1,472 KB) - Glacial terminations as southern warmings without northern control | Supplementary information

Subject Category: Palaeoclimate and palaeoceanography

Orbitally driven east–west antiphasing of South American precipitation - pp210 - 214

Francisco W. Cruz, Mathias Vuille, Stephen J. Burns, Xianfeng Wang, Hai Cheng, Martin Werner, R. Lawrence Edwards, Ivo Karmann, Augusto S. Auler & Hanh Nguyen

doi:10.1038/ngeo444

The variations of tropical precipitation are antiphased between the hemispheres on orbital timescales. A comparison between a speleothem record of precipitation in northeast Brazil and rainfall reconstructions from the rest of tropical South America shows that a similar antiphasing operated in the same hemisphere during the Holocene.

First Paragraph - Orbitally driven east-west antiphasing of South American precipitation | Full Text - Orbitally driven east–west antiphasing of South American precipitation | PDF (4,088 KB) - Orbitally driven east–west antiphasing of South American precipitation | Supplementary information

Subject Category: Palaeoclimate and palaeoceanography

Meridiani Planum sediments on Mars formed through weathering in massive ice deposits - pp215 - 220

Paul B. Niles & Joseph Michalski

doi:10.1038/ngeo438

Although a number of hypotheses have been put forward to explain the sulphate deposits discovered by the Opportunity rover at Meridiani Planum, Mars, the sedimentary layers remain enigmatic. A re-analysis of the chemistry, sedimentology and geology of the deposits suggests they formed through a reworking of the sublimation residue from a large-scale deposit of ice and dust.

Abstract - Meridiani Planum sediments on Mars formed through weathering in massive ice deposits | Full Text - Meridiani Planum sediments on Mars formed through weathering in massive ice deposits | PDF (1,511 KB) - Meridiani Planum sediments on Mars formed through weathering in massive ice deposits | Supplementary information

Subject Category: Planetary science

See also: related Backstory | News and Views by Hynek

Microbial dissolution of clay minerals as a source of iron and silica in marine sediments

John S. Vorhies & Robert R. Gaines

doi:10.1038/ngeo441

Interactions between microbes and minerals are evident in modern global elemental cycles. Relationships between minerals in Cambrian mudstones indicate that such interactions may have released otherwise unavailable, mineral-bound iron and silica into the ancient oceans.

Abstract - Microbial dissolution of clay minerals as a source of iron and silica in marine sediments | Full Text - Microbial dissolution of clay minerals as a source of iron and silica in marine sediments | PDF (1,389 KB) - Microbial dissolution of clay minerals as a source of iron and silica in marine sediments

Mercury methylation made easy - p172

Richard Sparling

doi:10.1038/ngeo445

Full Text - Mercury methylation made easy | PDF (83 KB) - Mercury methylation made easy

Seeing through the smoke - p228

doi:10.1038/ngeo459

Robert Field and colleagues turned their attention to the newspapers and used the simplest of weather observations to better understand the climatological and human causes of Indonesia's fire problem.

Full Text - Seeing through the smoke | PDF (209 KB) - Seeing through the smoke

See also: Letter by Field et al.

Mission Mars - pE3

doi:10.1038/ngeo457

Robin Fergason and colleagues sent a rover to Meridiani Planum to better understand the history of the red planet.

Full Text - Mission Mars | PDF (183 KB) - Mission Mars

See also: Article by Niles & Michalski

Unearthing the flow - pE4

doi:10.1038/ngeo458

Daniel Rothman and colleagues imaged underground water and made friends with a hatchet-wielding prisoner during their attempt to understand the mechanics of stream development.

Full Text - Unearthing the flow | PDF (319 KB) - Unearthing the flow

See also: Letter by Abrams et al.