Tag Archives: ocean

First Plants Caused Ice Ages

By Guest PostFebruary 1, 2012Environment, Natureatmospheric carbon, atmospheric carbon level, calcium, carbon cycle, carbonate rocks, chemical weathering, climate, earth surface, first land plants, global cooling, granite, ice ages, iron, liam dolan, magnesium, marine life, mass extinction, mineral, modern moss, ocean, ordovician period, oxford university, phosphorus, physcomitrella patens, reduction, rocks, silicate rocks, tim lenton, university of exeter

*New research reveals how the arrival of the first plants 470 million years ago triggered a series of ice ages. Led by the Universities of Exeter and Oxford, the study is published in Nature Geoscience.*

The team set out to identify the effects that the first land plants had on the climate during the Ordovician Period, which ended 444 million years ago. During this period the climate gradually cooled, leading to a series of ‘ice ages’. This global cooling was caused by a dramatic reduction in atmospheric carbon, which this research now suggests was triggered by the arrival of plants.

Among the first plants to grow on land were the ancestors of mosses that grow today. This study shows that they extracted minerals such as calcium, magnesium, phosphorus and iron from rocks in order to grow. In so doing, they caused chemical weathering of the Earth’s surface. This had a dramatic impact on the global carbon cycle and subsequently on the climate. It could also have led to a mass extinction of marine life. (more…)

New CU-led Study May Answer Long-Standing Questions About Enigmatic Little Ice Age

By Guest PostJanuary 30, 2012Environmentalps, Arctic sea ice, baffin island, bette otto bliesner, canadian arctic, China, climate feedback system, climate model, cooling effect, darren larsen, dead plant material, european glacier, feedback, gifford miller, greenland, ice, ice cap, kurt refsnider, langjökull ice cap, little ice age, london, melting icecaps, middle age, Netherlands, north atlantic ocean, norway, ocean, sea, sediment core, simulation, solar radiation, south america, thames river, tropical volcanic eruptions, volcanic aerosols, waterways, yafang zhong

A new University of Colorado Boulder-led study appears to answer contentious questions about the onset and cause of Earth’s Little Ice Age, a period of cooling temperatures that began after the Middle Ages and lasted into the late 19th century.

According to the new study, the Little Ice Age began abruptly between A.D. 1275 and 1300, triggered by repeated, explosive volcanism and sustained by a self- perpetuating sea ice-ocean feedback system in the North Atlantic Ocean, according to CU-Boulder Professor Gifford Miller, who led the study. The primary evidence comes from radiocarbon dates from dead vegetation emerging from rapidly melting icecaps on Baffin Island in the Canadian Arctic, combined with ice and sediment core data from the poles and Iceland and from sea ice climate model simulations, said Miller. (more…)

Sea Change – Penguins Provide Window into Shifting Antarctic Ecosystem

By Guest PostJanuary 29, 2012Environmentadelie penguins, Antarctic, chinstraps, climate change, ecosystem, environmental change, environmental dynamics, food web, gentoos, gliders, google earth, indicator species, kim bernard, krill, matthew oliver, nasa satellites, ocean, ocean substructure, ocean temperature, penguin, phytoplankton, predator, rising temperature, Rutgers University, south america, teresa messmore, travis miles, underwater robots, west antarctic peninsula

What’s the best way to study the Antarctic’s ecosystem? Follow the penguins.

Scientists are tracking penguins on land, under the sea, and even from space to unravel the environmental dynamics in the West Antarctic Peninsula as the region experiences climate change.

“We’re not just down there bird watching,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment. “This is a concerted effort to put the whole ecosystem together.” (more…)

Turtles’ Mating Habits Protect Against Effects of Climate Change

By Guest PostJanuary 27, 2012Environment, Natureannette broderick, baby turtle, breeding season, chelonia mydas, climate change, DNA, egg, global temperature, global warming, green turtle, health problem, inbreeding, kimberley stokes, lucy wright, marine turtle, mating habits, north africa, north cyprus society, northern cyprus, ocean, offspring, satellite tracking, temperature, turkey, university of exeter, university of lefke, warmer temperature

The mating habits of marine turtle may help protect them against the effects of climate change, according to new research led by the University.

Published on 25th January 2012 in Proceedings of the Royal Society B, the study shows how mating patterns of a population of endangered green turtles may be helping them deal with the fact that global warming is leading to a disproportionate number of females being born.

The gender of baby turtles is determined by the temperature of the eggs during incubation, with warmer temperatures leading to more females being born. Higher average global temperatures mean that offspring from some populations are predominantly female. This is threatening the future of some populations and there are concerns that inbreeding within groups due to a lack of males will lead to health problems. (more…)

Researchers Find Unprecedented, Man-Made Trends in Oceans Acidity

By Guest PostJanuary 26, 2012Environment21st century, acidity, anthropogenic co2 emission, aragonite, aragonite saturation, axel timmermann, bishop museum, calcification rate, calcium carbonate, caribbean, climate, climate modeler, co2 emission, computer modeling, coral, coral reef, earth system model, ecosystem, fossil fuel, global scale, hawaiian islands, honolulu, jamstec, jhamandas watumull planetarium, last glacial maximum, level of acidity, marine ecosystem, marine organism, mollusk, observation, ocean, ocean acidification, ocean chemist, ocean condition, parts per million, ppm, saturation level, tobias friedrich, western equatorial pacific, yellow tangs

Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.

By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)

University of Toronto/Royal Ontario Museum Scientists Discover Unusual ‘Tulip’ Creature

By Guest PostJanuary 20, 2012Nature, Scienceanimal, bizarre creature, burgess shale, burgess shale animals, calyx, canadian rockies, cup like structure, filter feeding system, fossil, fossil specimens, invertebrate palaeontology, jean bernard caron, lorna obrien, middle cambrian burgess shale, mount stephen, ocean, parks canada, primitive members, royal ontario museum, seafloor, siphusauctum gregarium, stem, tulip beds, UNESCO, university of toronto

*Lived in the ocean more than 500-million years ago*

A bizarre creature that lived in the ocean more than 500-million years ago has emerged from the famous Middle Cambrian Burgess Shale in the Canadian Rockies.

Officially named Siphusauctum gregarium, fossils reveal a tulip-shaped creature that is about the length of a dinner knife (approximately 20 centimetres) and has a unique filter feeding system. (more…)

Researchers Assess Radioactivity Released to the Ocean from the Fukushima Dai-Ichi Nuclear Power Facility

By Guest PostDecember 7, 2011Environmentbaltic and black seas, cesium 134, cesium 137, chernobyl accident, coastal waters, contamination, fate of radioactivity, fukushima dai ichi nuclear power plants, fukushima nuclear power plants, groundwater, history of contaminant, iodine 131, isotope, japan agency for marine earth science and technology, ken buesseler, levels of radioactivity, limnology, march 11 earthquake, marine biota, marine life, marine sediments, masao fukasawa, meteorological research institute, mext, michio aoyama, northwest coast of japan, ocean, ocean mixing processes, plants, radioactive leaks, radioactivity, radioactivity from fukushima, radionuclides, reactor facility, salt lake city, salt water basins, tepco, tsunami, woods hole oceanographic institution

With news this week of additional radioactive leaks from Fukushima nuclear power plants, the impact on the ocean of releases of radioactivity from the plants remains unclear. But a new study by U.S. and Japanese researchers analyzes the levels of radioactivity discharged from the facility in the first four months after the accident and draws some basic conclusions about the history of contaminant releases to the ocean.

The study, conducted by Woods Hole Oceanographic Institution chemist Ken Buesseler and two Japanese colleagues, Michio Aoyama of the Meteorological Research Institute and Masao Fukasawa of the Japan Agency for Marine-Earth Science and Technology, reports that discharges from the Fukushima Dai-Ichi nuclear power plants peaked one month after the March 11 earthquake and tsunami that precipitated the nuclear accident, and continue through at least July. Their study finds the levels of radioactivity, while quite elevated, are not a direct exposure threat to humans or marine life, but cautions that the impact of accumulated radionuclides in marine sediments is poorly known. (more…)

Bacterial Communication Could Affect Earth’s Climate

By Guest PostOctober 15, 2011Environmentatmospheric carbon dioxide, bacteria, bacterial communication, benjamin van mooy, british columbia, canada, carbon cycle, carbon dioxide, clayoquot sound, climate, heat trapping greenhouse gas, laura hmelo, marine plants, microscopic bacteria, ocean, particles, particles of carbon rich detritus, phytoplankton, planet, rose kantor, source of carbon, tiny marine animals, tracy mincer, university of washington, vancouver island, vessel barnes, whoi, woods hole oceanographic institution, zooplankton

Woods Hole Oceanographic Institution (WHOI) scientists have discovered that bacterial communication could have a significant impact on the planet’s climate.

In the ocean, bacteria coalesce on tiny particles of carbon-rich detritus sinking through the depths. WHOI marine biogeochemists Laura Hmelo, Benjamin Van Mooy, and Tracy Mincer found that these bacteria send out chemical signals to discern if other bacteria are in the neighborhood. If enough of their cohorts are nearby, then bacteria en masse commence secreting enzymes that break up the carbon-containing molecules within the particles into more digestible bits. It has been suggested that coordinated expression of enzymes is very advantageous for bacteria on sinking particles, and Hmelo and her colleagues have uncovered the first proof of this in the ocean. (more…)