* Astronomy

Members Login
Post Info TOPIC: Earths Water


L

Posts: 129914
Date:
RE: Earths Water
Permalink  
 


'Fossil' groundwater's modern secret

The world's oldest and deepest waters are not immune from contamination, warn scientists. It had been assumed that "fossil" reserves found hundreds of metres underground would be largely untouched by modern water sources.
But sampling from some 10,000 wells shows this not to be the case.
The new study reveals that about half of the deep groundwater has had contact with rains and snows that fell in the past 60 years.

Read more



__________________


L

Posts: 129914
Date:
Earth's oldest water
Permalink  
 


World's oldest water gets even older

The world's oldest water, which is locked deep within the Earth's crust, just got even older.
The liquid was discovered deep down in a mine in Canada in 2013 and is about 1.5 billion years old.
But now, at the same site, scientists from the University of Toronto have found a deeper source of water that is at least 500,000 years more ancient.

Read more



__________________


L

Posts: 129914
Date:
Earth's water
Permalink  
 


Earth's underground water quantified

The total amount of groundwater on the planet, held in rock and soil below our feet, is estimated to be 23 million cubic km.
If this volume is hard to visualise, imagine the Earth's entire land surface covered in a layer some 180m deep.
The new calculation comes from a Canadian-led team and is published in the journal Nature Geoscience.

Read more



__________________


L

Posts: 129914
Date:
RE: Earths Water
Permalink  
 


Title: Water delivery in the Early Solar System
Author: Rudolf Dvorak, Siegfried Eggl, Áron Süli, Zsolt Sándor, Mattia Galiazzo, Elke Pilat-Lohinger

As part of the national scientific network 'Pathways to Habitable Worlds' the delivery of water onto terrestrial planets is a key question since water is essential for the development of life as we know it. After summarizing the state of the art we show some first results of the transport of water in the early Solar System for scattered main belt objects. Hereby we investigate the questions whether planetesimals and planetesimal fragments which have gained considerable inclination due to the strong dynamical interactions in the main belt region around 2 AU can be efficient water transporting vessels. The Hungaria asteroid group is the best example that such scenarios are realistic. Assuming that the gas giants and the terrestrial planets are already formed, we monitor the collisions of scattered small bodies containing water (in the order of a few percent) with the terrestrial planets. Thus we are able to give a first estimate concerning the respective contribution of such bodies to the actual water content in the crust of the Earth.

Read more (47kb, PDF)



__________________


L

Posts: 129914
Date:
Permalink  
 

Title: The ancient heritage of water ice in the solar system
Author: L. Ilsedore Cleeves (1), Edwin A. Bergin (1), Conel M. O'D. Alexander (2), Fujun Du (1), Dawn Graninger (3), Karin I. Öberg (3), Tim J. Harries (4) ((1) University of Michigan (2) Carnegie DTM (3) Harvard-Smithsonian CfA (4) University of Exeter)

Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Utilizing a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, curtailing the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems.

Read more (6491kb, PDF)



__________________


L

Posts: 129914
Date:
Earth's water
Permalink  
 


Earth's Water is Older than the Sun

Water was crucial to the rise of life on Earth and is also important to evaluating the possibility of life on other planets. Identifying the original source of Earth's water is key to understanding how life-fostering environments come into being and how likely they are to be found elsewhere. New work from a team including Carnegie's Conel Alexander found that much of our Solar System's water likely originated as ices that formed in interstellar space. Their work is published in Science.
Read more



__________________


L

Posts: 129914
Date:
RE: Earths Water
Permalink  
 


Rainwater discovered at new depths

University of Southampton researchers have found that rainwater can penetrate below the Earths fractured upper crust, which could have major implications for our understanding of earthquakes and the generation of valuable mineral deposits.
It had been thought that surface water could not penetrate the ductile crust - where temperatures of more than 300°C and high pressures cause rocks to flex and flow rather than fracture - but researchers, led by Southamptons Dr Catriona Menzies, have now found fluids derived from rainwater at these levels.

Read more



__________________


L

Posts: 129914
Date:
Permalink  
 

Deep Canadian mine yields ancient water

Water drilled from rock in a North American mine is among the oldest yet found on Earth, say scientists.
Novel dating techniques used by the Canadian and UK team suggest the fluid is at least 1.5 billion years old.
The water was probably once on the surface and then percolated through the ground where it became trapped at a depth of 2.4km.
The discovery, made under Timmins, Ontario, is reported in this week's edition of the journal Nature.

Read more



__________________


L

Posts: 129914
Date:
Earth's water
Permalink  
 


Title: A Compound model for the origin of Earth's water
Authors: K. de Souza Torres, O. C. Winter, A. Izidoro, N. Haghighipour

One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which, local adsorption of water vapour onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water-delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyse our results comparing two different water distribution models, and complement our study using D/H ratio, finding possible relative contributions from each source, focusing on planets formed in the habitable zone. We find that the compound model play an important role by showing more advantage in the amount and time of water-delivery in Earth-like planets.

Read more (100kb, PDF)



__________________


L

Posts: 129914
Date:
Earths Water
Permalink  
 


The World's Oldest Water?

New evidence bolsters the notion that deep saline groundwaters in South Africa's Witwátersrand Basin may have remained isolated for many thousands, perhaps even millions, of years.
The study, recently accepted for publication in Chemical Geology, found the noble gas neon dissolved in water in three-kilometre deep crevices.
The unusual neon profile, along with the high salinities and some other unique chemical signatures, is very different from anything seen in molten fluid and gases rising from beneath the Earth's crust, according to University of Toronto professor Barbara Sherwood Lollar, who is the Canadian member of the international team that produced the results.

Read more



__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard