Archive for the ‘Geology’ Category
These have been obtained the first proof that already there were capable bacteria to breathe oxygen lodged in firm land some 100 million years earlier than previously thought. The form of primitive life on land aerobic respiration appeared 2,480 million years ago.
The research team, led by Kurt Konhauser, geomicrobiologist at the University of Alberta, Canada, has achieved this result after investigating a link between levels of atmospheric oxygen and increased concentrations of chromium in ancient seabed rocks. The researchers suggest that the increase in chromium levels was caused by the oxidation of pyrite land. Read the rest of this entry »
A new research will compare the amount of snow during the cold season, and melting of snow and ice that occurs during the warm season in Pyrenean glaciers, and study and its evolution. North Glacier, located in the Ordesa National Park and Monte Perdido in the Pyrenees of Aragon was the first to be scanned in three dimensions.
Researchers at the University of Zaragoza and the Pyrenean Institute of Ecology (IPE-CSIC) have applied a long-range laser scanner for mapping in three dimensions and high spatial resolution, each two feet, the surface of the glacier north.
This glacier from the Ordesa National Park and Monte Perdido is one of the most spectacular examples of the current Pyrenean glaciers. Photographs showing its evolution from the late nineteenth century served as a testimony of the great retreat of glaciers that have experienced the Pyrenees in recent decades. Read the rest of this entry »
Scientists have assumed for some time that the carbon cycle of Earth extends deep inside the planet, but until now there was no direct evidence. The mantle the thickest layer of the Earth is largely inaccessible.
It extends from 10 to 2,900 kilometers below the Earth’s surface. Some researchers, who include specialists from the Carnegie Institute in the U.S., have analyzed diamonds originating in the lower mantle at depths of 700 km or more, and came to the surface in rocks called kimberlites, expelled during volcanic eruptions. Read the rest of this entry »
Almost all oceanic islands are volcanoes. Several, like Hawaii, the material originated from Earth’s mantle.
This geological process begins with the rise of hot rock in cylindrical columns, from a depth of nearly 3,000 kilometers. Near the surface melts, because the pressure is lower, and form volcanoes. The plumes are the result of the rise of oceanic crust material before it sank to the bottom of the mantle in an old stage in the history of Earth. Read the rest of this entry »
Currently, molecular oxygen constitutes 21 percent of the air we breathe, which represents a significant portion of the Earth’s atmosphere. However, in the turbulent primordial gas mixture that characterized the atmosphere of our world in its distant past, there was little molecular oxygen, or maybe even was virtually nonexistent.
It was not until the Great Oxidation, about 2,300 million years, when oxygen started to have an appreciable influence on the atmosphere, stimulating the evolution of air-breathing organisms that were more complex, until finally allow the emergence of life just as we know it today.
Now, new research of MIT suggests that molecular oxygen may have formed on Earth hundreds of millions of years before it passed into the atmosphere, keeping discreetly in a series of ‘oxygen oases’ located in the oceans. Read the rest of this entry »
The ebb and flow of ocean tides is a phenomenon that generally is considered one of the most predictable on Earth. But in reality the scope of the tides varies considerably with the passage of long periods of time, in ways that have not been properly taken into account in most assessments of changes in the level of prehistoric seas.
Due to phenomena such as ice ages, plate tectonics, the processes of land elevation, erosion and sedimentation, the tides have changed dramatically through the millennia, and may change again in the future, as is revealed a new study conducted by the team of David Hill (Oregon State University).
Some tides on the East Coast of the United States, for example, could be several times the past much greater than today, presenting a difference between high tide and low of 3 to 6 meters, instead of the current 1 to 2 meters on average. Read the rest of this entry »
Carbonaceous chondrites are a type of meteorite rich in organic matter and contain samples of the materials involved in the creation of our planet nearly 4,600 million years. In fact, some of these materials probably formed even before our solar system, and could be crucial for the emergence of life on Earth.
The complex set of organic materials in carbonaceous chondrites may vary considerably from one meteorite to another.
New research shows that most of these variations are the result of hydrothermal activity that took place in the first few million years since the formation of the solar system, when meteorites were still part of larger bodies, probably asteroids. Read the rest of this entry »
The inner core (the innermost core of the earth) is fused and solidified simultaneously because of the heat flow in the rocky mantle that covers it, according to results of new research.
The discovery of this study could provide crucial clues to find out how the inner core was formed and exactly how the outer core acts as a dynamo, generating the planet’s magnetic field.
In many ways, the origin of the Earth’s magnetic field is still a mystery to scientists, such as Jon Mound of the University of Leeds, United Kingdom and a member of the research team.
Unable to go to collect samples at the center of the Earth, scientists have to rely on measurements taken well above as well as digital models, to try to get an idea of what’s happening in the nucleus. Read the rest of this entry »
For many years, the majority of scientists who study the Tibet have been thought that, at some depth under the base of the plateau, there is a portion of very hot and weak, bark that flows like a liquid. Now, a team of researchers questioned this entrenched belief and proposes that it is a completely different mechanism which acts there.
The area of Tibet and the Himalayas are among the most dynamic regions in the world. Collisions between tectonic plates in the basement of the Earth, causing earthquakes and the evolution of Tibet and the Himalayas, are common geological processes that have acted on many occasions throughout the history of the Earth, but now another with a vigor and energy just existing in that area. Read the rest of this entry »
Earthquakes are virtually impossible to predict, and capable of causing untold havoc in seconds.
Now, a new tool may enable us to learn from the distant past earthquakes, which could contribute their bit for work aimed at achieving better predictions of future earthquakes.
Seismic data, with some continuity and scientific rigor, which now has about earthquakes, only go back to little more than a century ago.
The team of Shmuel Marco, Eyal Hefetz and Nadav Wetzer, all of the University of Tel Aviv, has invented a new tool that describes as a kind of “Paleo Seismograph”, to help the geophysical and other researchers to obtain valuable data on the patterns of seismic activity in the past. Read the rest of this entry »