Showing posts with label earth. Show all posts
Showing posts with label earth. Show all posts

Monday, January 8, 2018

A Popular Tool to Trace Earth’s Oxygen History Can Give False Positives

false positives

Updated Tool – Tracing Oxygen

A latest investigation for researchers tracking the ancient history of oxygen in the atmosphere of the Earth could dampen their discovery thrills. According to the study an updated tool utilised in tracing oxygen on examining ancient rock strata could produce false positive and the wilful consequences could conceal the exciting results.

Ligands the commonly known molecules could bias the results of well-known chemical traced called chromium (Cr) isotope system. This is utilised in testing sedimentary rock layers for clues in relation to atmospheric oxygen levels during epoch while the rocks are being formed. Demonstration have been conducted in the lab by the researchers at the Georgia Institute of Technology that several ligands could have developed a signal akin to the molecular oxygen.

According to one of the lead authors of the research, Chris Reinhard, there are some geographical locations together with ancient situations wherein measurable signals could have been created which could have no connection with how much oxygen was everywhere. However, the new research could impact how some recent discoveries are evaluated with false positives, but that does not mean the tool is not useful.

Chromium Isotope System – Great Indicator of Atmospheric Oxygen Levels

Yuanzhi Tang, co-leading the study commented that they are not attempting to revolutionize the way the tool is viewed as false positives. It is about comprehending its possible limitation in discerning the use of it in particular cases.

The team’s results had been published in a study on November 17, 2017, in the journal Nature Communications, by Tang and Reinhard, assistant professors of biogeochemistry in Georgia Tech’s School of Earth and Atmospheric Sciences. Financial support had been provided by the NASA Astrobiology Institute, the NASA Exobiology program together with the Agouron Institute.

Tang had commented that on a global level, the chromium isotope system is yet a great indicator of atmospheric oxygen levels through the ages and the issue exposed in the lab tends to be more local with isolated samples, particularly during eras when there was not much atmospheric oxygen.

Ligands, deprived of a dominant oxygen presence tend to make a great reactive substitute as demonstrated by the researchers in reaction with chromium. Just like oxygen, ligands are inclined to strongly attract electron pairs, which is what symbolizes them as chemical group.

Earth – Massive Chemical Laboratory

Similar to reactions with oxygen, reactions with ligands permits metals such as chromium to move around with ease in the world. Researchers, in this instance, had been concerned in organic ligands, which tend to contain carbon.

They had been more suitable to counterpart the mobility effect of oxygen on chromium which made it end up as the signals in sedimentary rock that the scientists presently looked for as a sign of ancient atmospheric oxygen.

The chromium isotope system tends to work thus followed by how organic ligands tend to make for false positives – The Earth, a massive chemical laboratory performing reactions in conditions tend to differ from arctic cold to volcanic heat, thus from crushing ocean depths to no-pressure upper atmospheres. Waves and winds tend to sweep about the materials like turbulent conveyor belts, dropping some in sediments which later on turn to stone.

Earth Lacking O2

Chemical reaction that had been discovered in the research, including manganese oxide handing off oxygen to chromium could be somewhat like adding pontoons to chromium compounds. Earth’s atmosphere, for billions of years had been almost lacking of O2 though after oxygen had begun growing particularly in the last 800 million years, became the overbearing oxidizer.

 Characteristics of chromium deposits in ancient layers of rock had become a great indicator of how much O2 was in the atmosphere. Presently researchers tend to test deep rock layer samples for the link between two chromium isotopes, 53Cr, by far the most common Cr isotope while 53Cr to acquire a read on oxygen existence across geological eras.

According to Reinhard, `you powder the rock up, dissolve it with acid and then measure the ratio of 53Cr to 52Cr in the material by utilising mass spectrometry. It is the ratio which matters and will be controlled by a range of complex processes though generally speaking, elevated 53Cr in ocean sediment rock tends to indicate oxygen in the atmosphere’.

Cr Isotopes - Staple

Cr isotopes are said to be stable and do not go through radioactive decay and hence the system does not function the way radiocarbon dating does that depend on the decay of carbon 14. Tang’s team had portrayed in the lab with a small assortment of organic ligands that reaction of chromium with ligands had led to 53Cr/52Cr signals which had nearly represented those stemming from oxygen-chromium reactions.

Tang had mentioned that ligands tend to have the potential of mobilizing chromium also. Ligands in fact could be a significant factor in controlling chromium isotope signals in certain rock records. Organic ligands had probably been around much before the atmosphere of the Earth had been filled up with O2. Presently hundreds of millions of years thereafter, the reactions took place, and it is basically impossible to find out if oxygen or ligands had been at work.

Saturday, January 6, 2018

Puzzling patches in Earth’s interior billions of years in the making, Stanford researchers find


Scientific Anomaly – Insights to Deep Processes of Earth

According to Stanford researchers, chemical reaction with ancient seawater and iron in mantle over eons of the Earth illuminates the formation of mysterious blobs in the interior of the planet which tends to damp down passing seismic waves.

Scientists have been confused for decades, with these thin patches of dense rock which have been placed around 1,800 miles below the surface of the Earth, just above the core-mantle boundary which seems to isolate the molten metal heart of the planet from its rocky shell. They tend to be prominent from their surroundings since the seismic waves created by earthquakes tend to slow down by a tenth to a third of their usual speed when they sweep across.

These dampening zones, apart from being a scientific anomaly, could also offer insights in the other deep processes of the Earth according to research leader, Wendy Mao, an associate professor of geological sciences at School of Earth, Energy & Environmental Sciences of Stanford.

The information regarding the regions considered as ultra-low velocity zones or ULVZs takes place at the core-mantle boundary tends to be interesting since it recommends that the core and mantle of the Earth tends to interrelate to a much greater extent than had been earlier valued.

ULVZs – Origins of Molten Plumes 

According to Mao there is evidence that ULVZs are the origins of molten plumes which tend to feed volcanoes towards the surface and hence ULVZs could indicate a considerable amount of cycling between the core, mantle and surface of the Earth than speculated. The composite as well as the origins of the zones tend to remain a unknown owing to their extreme depths.

 However in the latest researcher published online in the journal Nature, which is an international team of researchers headed by Mao, have provided a new theory explaining how they tend to be formed. The device which has been proposed by them is established on their latest discovery of a novel kind of oxygen-rich iron compound which is inclined to form spontaneously in great heat and pressure, conditions which are present in the lowermost mantle region of the Earth.

Mao’s team while experimenting in the lab at Argonne National Laboratory in Illinois, had compressed slivers of iron foil suspended in pure water to around 90 gigapascals or about 900,000 times the pressure at sea level laser heating them to 3,000-4,000 degrees Fahrenheit.

Super-Oxygenated Iron 

The consequence of this is a super-oxygenated type of iron which is packed with around a third more oxygen molecule than the most oxygen rich oxides which tend to occur beneath the surface conditions. The team also portrayed that their compound shares several of the seismic waves dampening properties shown by the low velocity zones.

Jin Liu, study first author, a postdoctoral researcher in the lab of Mao stated that the low sound speeds calculated for compound tend to match precisely to what was observed seismically in ULVZs. Moreover, the oxygen-rich iron created by the team in the lab had the tendency to form easily at the core-mantle boundary.

Mao commented that this reaction needed only iron and water and as long as one has these components and the accurate temperature together with pressure conditions, this compound tend to form.

Wednesday, December 28, 2016

Watch the Earth Change before Your Eyes


Landscapes/Features of Earth Undergone Dramatic Change

Several of the landscapes and features of the Earth have undergone a dramatic change since 1984. Google has made its prime update to Time-lapse with addition of four years of imagery, big amounts of new data together with a sharper view of the Earth from 1984 to 2016.

Latest images by Google’s Time-lapse application portrays how the features comprising of Alaska’s Columbia glacier and Dubai’s extensive cityscape tend to have drastically progressed in the last 32 years. Its Time-lapse visualisation of Earth, had first been released by Google in 2013, offering the most comprehensive image of our changing planet, made available to the public.

The communicating time-lapse experience permits people in exploring changes to the surface of the Earth like never before from observing the sprouting of Las Vegas strip to the retreat of Alaska’s Columbia glacier. Moreover, it enables user in exploring a variety of compelling locations much further than 1984. For instance, in London, one can make out the progress of the City Airport and the Olympic stadium in Stratford. On zooming in on the Aral Sea it portrays how it has been drying since the 1960s owing to Soviet irrigation programmes.

New Time-lapse Show Sharper View of Planet

If the date is moved to 2007, the volume of the Aral Sea seems to be reduced to about 10% of its original size. For the time being, over the past three decades, Alaska’s Columbia Glacier is observed to have retreated over 12 miles.Another city which has undergone drastic changes since 1984 is New York.

 In comparison to 1984 to 2016, it shows how much progress has been made around the Central Park area and Brooklyn. Programme Manager at Google Earth Engine, Chris Herwig, had commented that `in leveraging the same techniques were used in improving Google Maps and Google Earth back in June, the new Time-lapse showed a sharper view of our planet, with truer colours and less distracting artefacts’.

He further informed that using Google Earth Engine, they had combined over 5,000,000 satellite images, approximately 4 petabytes of data in creating 33 images of the complete planet, one for each year. He added that for the latest update, they had access to more images from the past due to the Landsat Global Archive Consolidation Program together with fresh images from two new satellites, namely Landsat 8 and Sentinel-2.

USGS/NASA - Landsat

The 33 new terapixel global images were then encoded into just over 25,000,000 overlapping multi-resolution video tiles, making interactively explorable by Carnegie Mellon CREATE Lab’s Time Machine library, which is a technology in creating and inspecting zoomable as well as pannable time-lapses over space and time.

In order to explore the feature, one could type in the name of a place in the search bar and move the timeline towards the bottom in opting for the year one would prefer to view. Images had been initially collected as part of constant joint mission between the United States Geological Survey –USGS and NASA known as Landsat.

 The Landsat mission’s satellites since the 1970s had been observing the Earth from space. The images have been sent back to Earth and archived on USGS tape drives which is an achievement that is much stress-free with the present digital technology than with analog tape in the 1970s. In order to make this historic archive of earth imagery available online, Google began working with USGS in 2009.

Thursday, December 24, 2009

IS THE EARTH SLOWING DOWN ?!!!!!!!!!!!!!!!!!!!!!!

Do you know, The earth is slowing down? The rotational speed of the earth is slowing down. This was first found by the famous scientist,mathematician,astronomer Edmond Halley. A comet is bearing his own name as Comet Halley, to honor him for his remarkable job in astronomy.

The earths speed of rotation was slow down but the rate at which it takes place is very very small and it can not be accurately measured in a small interval of time. In 100 years or more a day or night will be two milliseconds longer. Now our earth takes 24hours to take one complete rotation on its own axis but about 400 million years before it was about 400days long.

Here we gave to remember again the moon is revolving around the earth more slowly and moves away from the earth few centimeters per year. The interaction of moon and earth are the result of the above interrelated phenomena.

we know gravitational pull of the moon and sun cause tides. Apart from these two the centrifugal force of the earth is also a reason for it. The height of the tides depends upon the shape of the coast, depth of the ocean and the shape of the Ocean bed.

The movement of water masses and tides makes some friction on the earth crest which absorbs some energy of the earth which works like a brake and slow down the earth's rotation.

As some time in future our planet will slowed its rotation and it will lose its own satellite moon. Further, after 4 thousand million years the earth will stop its rotation on its own axis which will result in dividing into two halves extreme hot and extreme cold region.