Date Time
Ancient sand reveals missing piece of 3.2-billion-year-old continent
Scientists have found evidence for a missing piece of a 3.2-billion-year-old continent, according to a new study by University of Alberta scientists. The research identifies the only remnant of ultra-hot lavas within this ancient landmass, located within tiny mineral grains preserved in sandstone.
“Our research developed a method to identify and date pieces of our ancient continents that until now have been lost to us,” said Rasmus Haugaard, who conducted the research during his PhD studies in the Faculty of Science. “This is crucial as it can improve how we model the evolution of Earth’s early continents.”
Arctic Journal
The next economic opportunity?
Luxuriant Arctic forests
In cold marine waters, rocky reefs are often dominated by habitat-forming seaweeds such as kelp. These seaweeds form impressive underwater forests that are not only a phenomenal source of primary productivity and food, but also create three- dimensional structure that provides valuable habitat for many animals and other seaweeds, including harvested species. The recipe for kelp forests in many regions of the world is deceptively simple: a rocky seafloor, enough light to support growth, cool nutrient-rich waters, and low grazing pressure to ensure survival. Add protection from ice scour to this mix and you have the formula for predicting the potential distribution of kelp in Arctic regions.
Massachusetts Institute of Technology
Nearly one quarter of the land in the Northern Hemisphere, amounting to some 9 million square miles, is layered with permafrost – soil, sediment, and rocks that are frozen solid for years at a time. Vast stretches of permafrost can be found in Alaska, Siberia, and the Canadian Arctic, where persistently freezing temperatures have kept carbon, in the form of decayed bits of plants and animals, locked in the ground.
Scientists estimate that more than 1,400 gigatons of carbon is trapped in the Earth’s permafrost. As global temperatures climb, and permafrost thaws, this frozen reservoir could potentially escape into the atmosphere as carbon dioxide and methane, significantly amplifying climate change. However, little is known about permafrost’s stability, today or in the past.
Credits: Courtesy of the researchers Terms of Use: Images for download on the MIT News office website are made available to non-commercial entities, press and the general public under a Creative Commons Attribution Non-Commercial No Derivatives license. You may not alter the images provided, other than to crop them to size. A credit line must be used when reproducing images; if one is not provided below, credit the images to MIT. Caption: Earth’s permafrost shifted to a more stable state in the last 400,000 years and has been less susceptible to thawing since then, according to a new study by MIT researchers and their colleagues, who are pictured here on a research expedition.
Cave deposits show surprising shift in permafrost over the last 400,000 years eurekalert.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from eurekalert.org Daily Mail and Mail on Sunday newspapers.