In the equatorial regions on Earth today, the seasonal cycle of the monthly mean surface air temperature is <10°C. However, deep (>1 m) sand wedges were found near the paleoequator in the Marinoan glaciogenic deposits at ~635 million years ago, indicating a large seasonal cycle (probably >30°C). Through numerical simulations, we show that the equatorial seasonal cycle could reach >30°C at various continental locations if the oceans are completely frozen over, as would have been the case for a snowball Earth, or could reach ~20°C if the oceans are not completely frozen over, as would have been the case for a waterbelt Earth. These values are obtained at the maximum eccentricity of the Earth orbit, i.e., 0.0679, and will be approximately 10°C smaller if the present-day eccentricity is used. For these seasonal cycles, theoretical calculations show that the deep sand wedges form readily in a snowball Earth while hardly form in a waterbelt Earth.
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http://dx.doi.org/10.1126/sciadv.aay2471 | DOI Listing |
J Environ Manage
December 2024
School of Geography and Ocean Science, Nanjing University, Xianlin Ave.163, 210023, Nanjing, China.
The complex life cycle traits of amphibians make them especially sensitive to environmental change, and their ongoing conservation requires the maintenance of suitable habitat that accounts for such life cycle characteristics which may impacted by local environmental dynamics arising from climate change and human disturbance. Many existing studies on amphibian habitats disregard this important issue, leading to uncertainty in managing critical habitats. The application of appropriate conservation practices is therefore constrained by the fact that the major factors influencing amphibian habitats, and their spatio-temporal dynamics at different life stages, are poorly understood.
View Article and Find Full Text PDFJ Environ Radioact
December 2024
Graduate School of Human Environment, Osaka Sangyo University, Osaka, 5748530, Japan.
Tritium, a radioactive isotope produced naturally through cosmic radiation interactions and anthropogenically through nuclear weapons testing, poses potential environmental risks, particularly within the water cycle. This study measured tritium concentrations in surface water across Thailand to establish a baseline dataset for monitoring potential contamination from nuclear activities and accidents. Surface water samples were collected from 14 large reservoirs during the wet season in October 2023 and the dry season in February 2024, providing a total of 28 samples.
View Article and Find Full Text PDFWater Res
December 2024
CSIRO Environment, Centre for Environment and Life Sciences, Private Bag No 5, Wembley, Western Australia 6913, Australia. Electronic address:
Harvesting of stormwater and injecting it into aquifers for storage and recovery during high water demand periods is a promising technology for augmenting conventional water reserves. However, little has been known on how stormwater impacts the biofouling of water distribution infrastructure. This study evaluated the effect on harvested and limestone aquifer treated stormwater on biofilm formation in a pilot distribution pipe network compared to an identical drinking water pipe rig.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, Govt. of India, NIOT Campus, Pallikaranai, Chennai 600 100, India. Electronic address:
Coastal lagoons, acting as transitional zones, are increasingly threatened by microplastic (MP) pollution. This study investigates the spatio-seasonal distribution of MPs in Chilika Lagoon sediments to propose effective mitigation measures. MPs were extracted using density flotation and wet peroxide oxidation, followed by quantitative analysis with a stereomicroscope and qualitative analysis with micro-Fourier Transform Infrared (μ-FTIR) spectroscopy.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Instituto de Ciências do Mar (LABOMAR), Universidade Federal do Ceará (UFC), Fortaleza, Brazil. Electronic address:
Estuaries are the main pathway for the microplastics (MPs) to enter into the oceans. However, factors that drive river-sea transport of MPs are not yet fully understood. Therefore, our research investigated the influence of the tidal cycle on the abundance and characteristics of MPs in an urban estuary, through high-frequency sampling (every 2-3 h) using a plankton net (120 μm mesh size) in two seasons (rainy and dry seasons).
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