snowball earth Archives

Snowball Earth -- Grok via Astrobiology.com

Arctic / Antarctic / Alpine, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

The Neoproterozoic Glacial Broom

by Keith CowingMarch 10, 2025March 9, 2025

Neoproterozoic snowball Earth events reflect globally frigid conditions thought to have stimulated changes in geochemical cycling with planetary biotic response. We investigated the impact of these events on sediment dynamics, […]

Photographs of Tava injectites within a darker-colored, red-brown to purple host comprising sandstone ridges. Outcrops (A) and (C) and their sketch overlays (B) and (D), respectively, showing 1st-(purple) and 2nd-(gold) generation injectites. Locations are North Cheyenne Canyon (A, B) and Manitou Springs (C, D). (A-B) are repeated from the main text figures but display further highlighted details. Study locations are shown in Fig. S2. -- PNAS

Astrogeology, Atmospheres, Climate, Weather, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Cryobiology, Extinction events, Habitable Zones, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Water/Hycean Worlds & Oceanography

Hematite U-Pb Dating Of Snowball Earth Meltwater Events

by Keith CowingDecember 2, 2024December 2, 2024

The Snowball Earth hypothesis predicts global ice cover; however, previous descriptions of Cryogenian (720-635 Ma) glacial deposits are limited to continental margins and shallow marine basins.

Slushy Snowball Earth -- Grok via Astrobiology.com

Arctic / Antarctic / Alpine, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Icy Worlds, Press Release, Terraforming & Geoengineering, Water/Hycean Worlds & Oceanography

New Evidence Of When Earth Was Slushy

by Keith CowingNovember 7, 2024November 7, 2024

At the end of the last global ice age, the deep-frozen Earth reached a built-in limit of climate change and thawed into a slushy planet.

A person looks at cap carbonate rocks in South China in 2019. The new study provides a new explanation for dramatic global environmental changes that led to their formation. Credit Yarong Liu

Analog Studies, Arctic / Antarctic / Alpine, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Cryobiology, Extinction events, Fossils & Paleontology, Habitable Zones, Icy Worlds, Press Release

Explaining Dramatic Planetwide Changes After The Last Snowball Earth Event

by Keith CowingSeptember 19, 2024September 19, 2024

Some of the most dramatic climatic events in our planet’s history are “Snowball Earth” events that happened hundreds of millions of years ago, when almost the entire planet was encased […]

Model benchmark against the modern climate system. Histograms show the results for observable variables from 1000 model runs where uncertain parameters are sampled. The vertical shaded regions are the measured or assumed modern values. (a, b, c) We assume the pre-industrial modern climate had 280 ppm atmospheric CO2, 285 K surface temperature, and 8.2 ocean pH. (d) The calcite and aragonite saturation states of the modern ocean vary from over 5 at the surface to below 0.5 in the deep ocean (Pilson 2012). (e) Estimates of continental carbonate weathering are from Hartmann et al. (2009), continental silicate weathering are from Moon et al. (2014), and seafloor weathering are from Coogan & Gillis (2013) and Krissansen-Totton et al. (2018). (f) Estimates of neritic carbonate deposition are from Iglesias-Rodriguez et al. (2002) and pore-space deposition are from Gillis & Coogan (2011) and Krissansen-Totton et al. (2018). -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Three-stage Formation of Cap Carbonates after Marinoan Snowball Glaciation Consistent with Depositional Timescales and Geochemistry

by Keith CowingAugust 20, 2024

At least two global “Snowball Earth” glaciations occurred during the Neoproterozoic Era (1000-538.8 million years ago). Post-glacial surface environments during this time are recorded in cap carbonates: layers of limestone […]

One exposed outcrop of the formation, found on Scottish islands called the Garvellachs, is unique as it shows the transition into “snowball Earth” from a previously warm, tropical environment.

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Press Release, Water/Hycean Worlds & Oceanography

Scottish And Irish Rocks Confirmed As Being A Rare Record Of Snowball Earth

by Keith CowingAugust 17, 2024August 17, 2024

The study, published in the Journal of the Geological Society of London, found that the Port Askaig Formation, composed of layers of rock up to 1.1km thick, was likely laid […]

Arctic / Antarctic / Alpine, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Extremeophiles and Extreme Environments, Habitable Zones, Icy Worlds, Origin & Evolution of Life, Status Report

Experimental Snowball Earth Viscosity Drives the Evolution of Motile Multicellularity

by Keith CowingAugust 13, 2024August 13, 2024

During the 70-million-year span of the Cryogenian Snowball Earth glaciations, low ocean temperatures beneath global sea ice increased water viscosity up to fourfold.

Surface temperature and sea ice thickness for simulations with varying drag timescales (column titles), for a SubCont planet with 20% dayside land, 8 bars of N2, and an instellation of 881.7 W/m2 . As the drag timescale decreases, heat transport to the nightside is inhibited and the planet remains in an eyeball state, which suggests that advection plays an important role in the climate transition. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report

Climate Transition to Temperate Nightside at High Atmosphere Mass

by Keith CowingAugust 10, 2024August 10, 2024

Our recent work shows how M-Earth climates and transmission spectra depend on the amount of ice-free ocean on the planet’s dayside and the mass of N2 in its atmosphere. M-Earths […]

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Resilience of Snowball Earth to Stochastic Events

by Keith CowingJuly 23, 2024July 22, 2024

Earth went through at least two periods of global glaciation (i.e., “Snowball Earth” states) during the Neoproterozoic, the shortest of which (the Marinoan) may not have lasted sufficiently long for […]

Temperate exoplanet LHS 1140 b may be a world completely covered in ice (left) similar to Jupiter’s moon Europa or may be an ice world with a liquid substellar ocean and a cloudy atmosphere (centre). LHS 1140 b is 1.7 times the size of our planet Earth (right) and is the most promising habitable zone exoplanet yet found in the search for liquid water beyond the Solar System. CREDIT Benoit Gougeon, Université de Montréal

Astropharmacy / Biotechnology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

Webb Telescope Finds A Potentially Habitable Icy World

by Keith CowingJuly 11, 2024July 11, 2024

A international team of astronomers led by Université de Montréal has made an exciting discovery about the temperate exoplanet LHS 1140 b: it could be a promising “super-Earth” covered in […]