Geoscience News

Ultralow-Velocity Zones are Leftovers from Early Earth’s Magma Ocean, New Study Suggests

Pachhai et al. employ seismic data analysis and high-resolution geodynamic modeling to study the origin of ultralow-velocity zones beneath the Coral Sea between Australia and New Zealand. Image credit: Pachhai et al., doi: 10.1038/s41561-021-00871-5.
Jan 3, 2022 by News Staff

Ultra-low velocity zones sit beneath the central Pacific and Africa, atop the outer core of Earth. In these areas, seismic waves slow by as much as half, and density goes up by a third. Geoscientists initially thought that these zones were areas where the mantle was partially melted, and might be the source of magma for hot spot volcanic regions like Iceland. New research suggests that it’s possible some of ultra-low velocity zones are leftovers...

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Long-lived lakes of water vapor in the atmosphere are observed to occur over the western Indian Ocean. Their dynamics resemble those of a well-studied theoretical and simulation paradigm for tropical disturbances called self-aggregation. Image credit: Mapes & Tsai.

New Meteorological Phenomenon Discovered: Atmospheric Lakes

Dec 30, 2021 by News Staff

Atmospheric lakes are long-lived pools of water vapor that occur over the western Indian Ocean and bring water to dry lowlands along East Africa’s coastline. Long-lived...

Oxygen deficient zone intensity across the eastern Pacific Ocean, where copper colors represent the locations of consistently lowest oxygen concentrations and deep teal indicates regions without sufficiently low dissolved oxygen. Image credit: Jarek Kwiecinski & Andrew Babbin.

High-Resolution Atlas of Pacific Ocean’s Oxygen Deficient Zones Created

Dec 28, 2021 by News Staff

A duo of MIT researchers has created the most detailed atlas of the world’s largest oxygen deficient zones, biogeochemical regions of the global ocean...

A valley in the Atacama Desert in Chile. Image credit: S. McMurtrey / CC BY-SA 4.0.

Iodine from Desert Dust Decreases Ozone Air Pollution, New Study Shows

Dec 23, 2021 by News Staff

Iodine, the same chemical added as a nutrient to table salt, is an atmospheric trace element emitted from oceans that efficiently destroys ozone. Low ozone...

An illustration depicting the onset of the end-Permian mass extinction. Image credit: Dawid Adam Iurino / PaleoFactory, Sapienza University of Rome / Jurikova et al, doi: 10.1038/s41561-020-00646-4.

Toxic Microbes Helped Cause and Prolong End-Permian Marine Mass Extinction, Study Suggests

Dec 20, 2021 by News Staff

Extreme warming at the end of the Permian period induced profound changes in marine biogeochemical cycling and animal habitability, leading to the largest...

Study area and hybrid-frequency waveform earthquakes (EHWs): (a) hydraulic fracturing activity and seismicity in northeast British Columbia, Canada; the top-right inset shows the geographic location of the study area (red rectangle); blue diamonds: hydraulic fracturing injection wells between January 1, 2014 and December 31, 2016, reported by the British Columbia Oil and Gas Commission; yellow dots: earthquakes during the same period; stars: 10 M 4-5 earthquakes since 2008; black rectangle: study area in which EHWs occurred; (b, c) comparison between representative examples of a typical induced event (black trace) and an EHW (purple trace); both waveforms are from the vertical component of station MG03 with comparable source-station distance (1.32 km vs. 1.65 km) and magnitudes (MW1.5); manually picked P/S-arrivals are marked; the comparison of P/S-pulse shape demonstrates the relatively wider pulses for EHWs; (d, e) the same as (b) and (c) but for waveforms recorded at station MG02; both events show longer coda durations with slightly larger epicentral distances; note that although both types of events have extended coda durations, the EHW contains a relatively larger proportion of lower-frequency energy in the coda. Image credit: Yu et al., doi: 10.1038/s41467-021-26961-x.

Scientists Detect New Type of Fluid-Injection-Induced Earthquake

Dec 6, 2021 by News Staff

Unlike conventional earthquakes of the same magnitude, the newly-identified hybrid-frequency waveform earthquakes are slower and last longer. Study area...

This diamond from Botswana contains tiny inclusions of davemaoite. Image credit: Aaron Celestian, Natural History Museum of Los Angeles County.

New Mineral Found inside Deep-Mantle Diamond: Davemaoite

Nov 17, 2021 by News Staff

Calcium silicate perovskite (CaSiO3) is arguably the most geochemically important phase in the Earth’s lower mantle, because it concentrates elements...

Tang Dynasty mural commemorating the victory of General Zhang Yichao over the Tibetans in 848 CE, from Mogao cave 156.

Volcanic Eruptions Contributed to Repeated Collapse of Ancient Chinese Dynasties, Says New Study

Nov 12, 2021 by News Staff

One or more volcanic eruptions preceded the majority (62 of 68) of dynastic collapses in China over the past 2,000 years, according to new research led...

An artist’s impression of the Hadean Earth: huge, impact-generated lava lakes coexisted with surface liquid water, under a thick greenhouse atmosphere sustained by lava outgassing. Image credit: Simone Marchi & Dan Durda, Southwest Research Institute.

Extreme Heat Led to Episodic Deluges on Ancient ‘Hothouse’ Earth, Scientists Say

Nov 4, 2021 by News Staff

The distant past of Earth and potentially its future include extremely warm ‘hothouse’ climate states, but little is known about how the atmosphere...

Ordovician sea life. Image credit: Fritz Geller-Grimm / National Museum of Natural History / CC BY-SA 2.5.

New Research Explores Cause of End-Ordovician Mass Extinction

Nov 2, 2021 by News Staff

The end-Ordovician mass extinction, the first of the ‘Big Five’ mass extinctions occurred 445 million years ago and was characterized by the disappearance...

This artistic conception illustrates large asteroids penetrating Earth’s oxygen-poor atmosphere. Image credit: SwRI / Dan Durda / Simone Marchi.

Archean Asteroid Impacts Delayed Evolution of Earth’s Atmosphere, Study Suggests

Oct 21, 2021 by News Staff

A team of researchers from the United States and Austria has analyzed remnants of ancient asteroids and modeled the effects of their violent collisions...

The supercontinent Nuna about 1.59 billion years ago. Image credit: Alexandre DeZotti.

Mantle beneath Earth’s Continents Experienced Large-Scale Heating Two Billion Years Ago

Sep 24, 2021 by News Staff

New research from the University of Adelaide sheds light on why cold eclogites — high-pressure, metamorphic rocks that consist primarily of garnet...

Earth’s magnetic field lines. Image credit: NASA’s Goddard Space Flight Center.

Study Provides Further Evidence of 200-Million-Year-Long Cycle in Strength of Earth’s Magnetic Field

Aug 20, 2021 by News Staff

New research shows that the magnetic field of our planet was relatively weak (less than half the strength of the long-term average field) for tens of millions...

Reconstruction of the West Antarctic mid-Cretaceous temperate rainforest. The painting is based on paleofloral and environmental information inferred from palynological, geochemical, sedimentological and organic biomarker data obtained from cores at the site of PS104_20-2, Antarctica. Image credit: J. McKay / Alfred-Wegener-Institut / CC-BY 4.0.

Decline in Atmospheric Carbon Dioxide Caused Eocene-Oligocene Cooling, Study Says

Aug 3, 2021 by News Staff

New research shows that mean annual temperatures in southeast Australia gradually declined from 27 degrees Celsius during the Middle Eocene epoch to...

An artist’s impression of the Hadean Earth: huge, impact-generated lava lakes coexisted with surface liquid water, under a thick greenhouse atmosphere sustained by lava outgassing. Image credit: Simone Marchi & Dan Durda, Southwest Research Institute.

Earth’s Early Bombardment May Have Been Heavier than Previously Thought

Jul 9, 2021 by News Staff

Once the Earth was fully formed about 4.5 billion years ago, its subsequent evolution was governed by complex geophysical processes. The planet, however,...

An artist’s impression of a ‘Snowball Earth.’ Image credit: NASA.

Changes in Our Planet’s Orbit May Have Allowed Life to Survive during ‘Snowball Earth’ Glaciations

Jul 8, 2021 by News Staff

A team of researchers led by Chinese Academy of Sciences’ Professor Ross Mitchell has studied a succession of rocks laid down when most of Earth’s...

Geologic Activity on Earth Follows 27.5-Million-Year Cycle, New Study Says

Jun 18, 2021 by News Staff

In a new study published in the journal Geoscience Frontiers, a team of U.S. researchers analyzed the ages of 89 well-dated geological events of the last...

An artistic conception of the early Earth. Image credit: Simone Marchi / NASA.

Earth’s Continental Crust First Emerged 3.7 Billion Years Ago

Apr 29, 2021 by News Staff

Reconstructing the emergence and weathering of Earth’s continental crust in the Archean eon is crucial for our understanding of early ocean chemistry,...

Life may have begun shortly after Earth formed 4.54 billion years ago. Image credit: Hadeano.

Permanent Oxygenation of Earth’s Atmosphere Occurred Later than Previously Thought

Apr 6, 2021 by News Staff

Oxygen levels fluctuated dramatically for about 200 million years after the start of the Great Oxidation Event, with permanent atmospheric oxygenation...

An illustration of early Earth, as it would have looked around 4 billion years ago. Image credit: Lucy Entwisle.

Lightning Strikes Played Role in Creating Prebiotic Phosphorus on Early Earth, Study Suggests

Mar 18, 2021 by News Staff

Phosphorus is one of the key elements for life, involved in biomolecules such as DNA, RNA, phospholipids, and adenosine triphosphate. Phosphide minerals...

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