On the Subject of Geology

[lovemarie]

Geology is an earth science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body (such as the geology of the Moon or Mars).

Here you can post pictures, videos, and everything you want about Geology.



Basics of Geology
Many ways lead to geology, whether it's the rocks along the road, the threat of climate change or the sights from your vacation. Here are the major avenues.

Rocks

Rocks are what the Earth is made of. The first thing geologists learn is how to observe, describe and classify rocks.


Minerals and Gemstones

Minerals are the ingredients of rocks. Just a few important minerals account for the majority of rocks and for the soil, mud and sand of the Earth's surface. Many of the most beautiful minerals are treasured as gemstones.


Earth Resources

Many rocks and minerals are important for civilization. They are products we take from the Earth. Learn more about their geology.


Geologic Processes
Geology is not just rocks and minerals, but also the things that happen to them in the great Earth cycle.


Geologic Hazards

Hazards are ordinary geologic processes that interfere with human life. (earthquakes, volcanic eruptions etc.)


Landforms

The hills, valleys and other features of a landscape are signs of the area's underlying structure and clues to its history.


Geologic Time
All of human history is the briefest moment at the end of four billion years of geologic time. How do geologists measure and order the milestones in Earth's long history?


Fossils

Fossils are precious gifts from the geologic past: signs and remains of ancient living things that help explain how life has coexisted with Earth. Fossils are an important line of evidence showing how life has evolved since its still-mysterious beginnings.


Evolution and Extinction

The consistent parade of fossil species through geologic time shows that life has been evolving since its remote beginning. Modern genetics tells the same story. Geology also shows that species have gone extinct.


Parts of the Earth

Beneath the stony crust lie the rocky mantle and, at Earth's heart, the iron core. All are areas of active research and competing theories.


Plate Tectonics
Plate tectonics is the first theory that explains the mechanics of the Earth's surface in depth, in detail and in a scientifically fruitful way.


Geology of Other Planets
The space program has revolutionized geology by giving us other examples of planets besides our own: they include Mercury, Venus, the Moon, Mars, the asteroids and the larger planetary satellites.

*geology.about.com

[jamesbond]

Diamond
The most popular gemstone.   The hardest known substance.   An amazing number of uses.

What is Diamond?


Diamond is a rare, naturally-occurring mineral composed of carbon. Each carbon atom in a diamond is surrounded by four other carbon atoms and connected to them by strong covalent bonds. This simple, uniform, tightly-bonded arrangement yields one of the most durable substances known.

Diamond is a fascinating mineral. It is chemically resistant and it is the hardest known natural substance. These properties make it suitable for use as a cutting tool and for other uses where durability is required. Diamond also has special optical properties such as a high index of refraction, high dispersion and high luster. These properties help make diamond the world's most popular gemstone.

Diamonds are a bit of a mystery. They are composed of the element carbon and because of that many people believe that they must have formed from coal. Many teachers still teach this in their classrooms. But that is not true!

largest uncut diamonds in the world....









and the largest cut diamonds ever produced....

[lovemarie]

Major volcanic eruptions can have a significant effect on the flow of the world’s biggest rivers, research shows.

In the first study of its kind, scientists sought to better understand how big volcanic eruptions, which can trigger a shortage of rainfall in many regions of the world, can impact on rivers.

Their findings could help scientists predict how water availability in regions throughout the world might be affected by future eruptions.

 
Rainfall changes
Researchers sought to learn more about the impact of a process in which volcanoes give off aerosol particles that reflect sunlight, cooling the atmosphere and leading to reduced rainfall.

A team from the University of Edinburgh analysed records of flow in 50 major rivers.

Their study spanned the dates of major eruptions, from Krakatoa in 1883 to Pinatubo in 1991.

The team grouped rivers by region to help identify the influence of volcanoes, and used computer models linking rainfall with eruptions to predict where rivers were likely to be affected.

Regional patterns
They found that eruptions were followed a year or two later by reduced flow in some rivers.

In general, this was found in tropical regions and northern Asia, and included the Amazon, Congo and Nile.

However, flow increased in some sub-tropical regions, owing to disruption to atmospheric circulation patterns.

Areas affected included the south-west US and parts of South America.

Human impact
Predicting how changes to river flow might impact on people is not straightforward, researchers say.

The Amazon is in a sparsely populated area, so reduction in its flow may have little impact.

However, for rivers with high levels of human dependence, such as the Nile, loss of flow could have more impact.

Their study, published in Nature Geoscience, was supported by the Natural Environment Research Council and the European Research Council.

Reference:
Carley E. Iles, Gabriele C. Hegerl. Systematic change in global patterns of streamflow following volcanic eruptions. DOI: 10.1038/ngeo2545

Note: The above post is reprinted from materials provided by University of Edinburgh.

[jamesbond]

. . . . . . . . . . . . .

[lovemarie]

Scientists pave way for diamonds to trace early cancers




Physicists from the University of Sydney have devised a way to use diamonds to identify cancerous tumours before they become life threatening.

Their findings, published in Nature Communications, reveal how a nanoscale, synthetic version of the precious gem can light up early-stage cancers in non-toxic, non-invasive Magnetic Resonance Imaging (MRI) scans.

Targeting cancers with tailored chemicals is not new but scientists struggle to detect where these chemicals go since, short of a biopsy, there are few ways to see if a treatment has been taken-up by a cancer.

 
Led by Professor David Reilly from the School of Physics, researchers from the University investigated how nanoscale diamonds could help identify cancers in their earliest stages.

"We knew nano diamonds were of interest for delivering drugs during chemotherapy because they are largely non-toxic and non-reactive," says Professor Reilly.

"We thought we could build on these non-toxic properties realising that diamonds have magnetic characteristics enabling them to act as beacons in MRIs. We effectively turned a pharmaceutical problem into a physics problem."

Professor Reilly's team turned its attention to hyperpolarising nano-diamonds, a process of aligning atoms inside a diamond so they create a signal detectable by an MRI scanner.

"By attaching hyperpolarised diamonds to molecules targeting cancers the technique can allow tracking of the molecules' movement in the body," says Ewa Rej, the paper's lead author.

"This is a great example of how quantum physics research tackles real-world problems, in this case opening the way for us to image and target cancers long before they become life-threatening," says Professor Reilly.

The next stage of the team's work involves working with medical researchers to test the new technology on animals. Also on the horizon is research using scorpion venom to target brain tumours with MRI scanning.

Reference:
Ewa Rej, Torsten Gaebel, Thomas Boele, David E.J. Waddington, David J. Reilly. Hyperpolarized nanodiamond with long spin-relaxation times. Nature Communications, 2015; 6: 8459 DOI: 10.1038/ncomms9459

Note: The above post is reprinted from materials provided by University of Sydney.

[naruto789544]

interesting subject.... geology encompasses the whole earth since even the oceans also have land masses underneath them... 

[lovemarie]

very true sir @naruto789544, Geology is a vast and indeed very interesting subject. i hope you are enjoying this thread of ours.

[jamesbond]

honga eh... iba nga ang subject na geology... parang bumabalik ako sa grade school ulit kapag bumabalik ang mga touched terms about geo.... like yung composition ng earth's core, mantle crust, etc... did you know that Manila geographical development is unplanned? hmmm... many eyebrows will raise here hehehehe.... kung planned ang engineering and geographical dev't nito eh di sana hindi bumabaha yan... ang typical planned city should be rectangular ang sukat ng mga lote or sqare man lang, eh manila is not that type, iba iba ang hugis ng sukat ng mga lupa... Manila is 5 meters below sea level kaya naman ang rain waters hindi makalabas papuntang ocean kasi mas mataas na ang dagat kesa sa ilalabas na tubig... hmmm... just a 5 cent share po.... 

[lovemarie]

Earth's inner core was formed 1-1.5 billion years ago
 


The inner core is Earth’s deepest layer. It is a ball of solid iron just larger than Pluto which is surrounded by a liquid outer core. The inner core is a relatively recent addition to our planet and establishing when it was formed is a topic of vigorous scientific debate with estimates ranging from 0.5 billion to 2 billion years ago.
Credit: Kay Lancaster, Department of Earth, Ocean and Ecological Sciences

There have been many estimates for when the earth's inner core was formed, but scientists from the University of Liverpool have used new data which indicates that the Earth's inner core was formed 1 -- 1.5 billion years ago as it "froze" from the surrounding molten iron outer core.

The inner core is Earth's deepest layer. It is a ball of solid iron just larger than Pluto which is surrounded by a liquid outer core. The inner core is a relatively recent addition to our planet and establishing when it was formed is a topic of vigorous scientific debate with estimates ranging from 0.5 billion to 2 billion years ago

In a new study published in Nature, researchers from the University's School of Environmental Sciences analysed magnetic records from ancient igneous rocks and found that there was a sharp increase in the strength of the Earth's magnetic field between 1 and 1.5 billion years ago.

 
This increased magnetic field is a likely indication of the first occurrence of solid iron at Earth's centre and the point in Earth's history at which the solid inner core first started to "freeze" out from the cooling molten outer core.

Liverpool palaeomagnetism expert and the study's lead author, Dr Andy Biggin, said: "This finding could change our understanding of the Earth's interior and its history."

"The timing of the first appearance of solid iron or "nucleation" of the inner core is highly controversial but is crucial for determining the properties and history of the Earth's interior and has strong implications for how the Earth's magnetic field -- which acts as a shield against harmful radiation from the sun, as well as a useful navigational aid -- is generated.

"The results suggest that the Earth's core is cooling down less quickly than previously thought which has implications for the whole of Earth Sciences. It also suggests an average growth rate of the solid inner core of approximately 1mm per year which affects our understanding of the Earth's magnetic field."

The Earth's magnetic field is generated by the motion of the liquid iron alloy in the outer core, approximately 3,000 km beneath the Earth's crust. These motions occur because the core is losing heat to the overlying solid mantle that extends up to the crust on which we live producing the phenomenon of convection.

Once the inner core started to freeze, this convection received a strong boost in power because light, non-metallic elements remained molten in the outer core and were buoyant relative to the overlying liquid. The process continues today and is thought to be the main source of "fuel" for generating the Earth's magnetic field.

Dr Biggin added: "The theoretical model which best fits our data indicates that the core is losing heat more slowly than at any point in the last 4.5 billion years and that this flow of energy should keep the Earth's magnetic field going for another billion years or more.

"This contrasts sharply with Mars which had a strong magnetic field early in its history which then appears to have died after half a billion years."

The study, published in the journal Nature, is a collaboration between scientists at the Universities of Liverpool, Helsinki, Michigan Tech, UC San Diego, and the Chinese Academy of Sciences.

Reference:
A. J. Biggin, E. J. Piispa, L. J. Pesonen, R. Holme, G. A. Paterson, T. Veikkolainen, L. Tauxe. Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation. Nature, 2015; 526 (7572): 245 DOI: 10.1038/nature15523

Note: The above post is reprinted from materials provided by University of Liverpool.

[lovemarie]

Efficiently Predicting Shallow Landslide Size and Location



 
Landslides from recently logged steep slopes dumped millions of tons of mud and debris into Stillman Creek,  near Curtis, Wash., in December 2007. Landslides like these may be easier to predict thanks to a new search algorithm derived from quantitative slope stability models.
Credit: David Perry


Because landslides can destroy property and reshape landscapes, scientists seek to predict when they will strike and to model their behavior. Previous work revealed that location and size are the most important characteristics that determine the impacts of shallow landslides less than a few meters deep. However, modeling these parameters presents unique challenges to researchers.

One common strategy involves digitally representing the landscape as a grid of adjacent cells or blocks with different physical properties, such as elevation, slope, soil depth, and pore pressure. This approach allows researchers to simulate the landscape in three dimensions, incorporate variation between cells, and account for the lateral effects of friction and plant root reinforcement.

 
However, the spatial arrangement of groups of unstable grid cells is not known. To overcome this issue, the computer could try to test every possible arrangement of blocks, but this strategy becomes computationally demanding or even impossible as the number of blocks increases. The authors point out that testing a 1-square-kilometer area composed of 1 million blocks generates 21,000,000 possible arrangements—a computational task beyond even our best computers.

To help reduce this burden, Bellugi et al. developed a search algorithm—a sequence of computer operations—that analyzes hillslope properties and outputs clusters of unstable blocks, allowing larger swaths of land to be analyzed using the gridded cell method. The team tested their new model on a virtual hillside as well as on data obtained from a landslide in Coos Bay, Ore. The algorithm performed well in both cases, allowing scientists to predict the location and approximate size of landslides with useful accuracy.

The results should allow future teams to better understand how shallow landslides develop in three dimensions without the need for such arduous computation. They should also give scientists the ability to scout for hazardous conditions that might cause loss of human life or property.

Reference:
hultz, D. (2015), Efficiently predicting shallow landslide size and location, Eos, 96, DOI:10.1029/2015EO037063. Published on 8 October 2015.

Note: The above post is reprinted from materials provided by American Geophysical Union. The original article was written by David Shultz.

[jamesbond]

mahirap talaga kapag landslide na.... i think what causes such was brought about by the deforestations and subsequent mining activities, not to mention the normal movement of the earth's crust...

[lovemarie]

Scientists track speed of powerful internal waves


These two figures show the internal waves at Dongsha Island on April 23, 2010, as seen by the radar on TerraSAR-X in its conventional mode of operation (left) and in the experimental new mode that permits direct velocity measurements (right), with the measured surface velocities shown in color. Red and blue colors indicate surface velocities of about 0.5 m/s to the left and to the right, respectively. The shown area is 30 km × 80 km. Dongsha Island, which is about 2.7 km × 0.9 km (1.7 mi × 0.6 mi) in size, can be seen near the center of the image.
Credit: German Aerospace Center (DLR) 2010.


For the first time researchers directly measured the speed of a wave located 80 meters below the ocean's surface from a single satellite image. The new technique developed by researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is a major advancement in the study of these skyscraper-high internal waves that rarely break the ocean surface.

"This is the first time internal wave velocities could be calculated from data acquired during a single overpass of a satellite," said Roland Romeiser, associate professor of ocean sciences at the UM Rosenstiel School. "This allows us to obtain more accurate information from a satellite that we could in the past."

Using a single satellite image collected at UM's Center for Southeastern Tropical Remote Sensing (CSTARS), the research team was able to determine that a roughly 60-meter high internal wave was traveling at a speed of three miles per hour (1.4 meters per second) near Dongsha Island in the South China Sea. The region is considered to have some of the most powerful internal waves on the planet.

"This is a significant breakthrough using a single image to determine the velocity of a wave below the surface," said Hans Graber, UM Rosenstiel School professor of ocean sciences and director of CSTARS. "This technology offers new opportunities to track the speed of ocean currents or objects moving on or below the ocean surface."

Internal waves move huge volumes of heat, salt, and nutrient rich-water across the ocean, which is important to fish, industrial fishing operations and the global climate. In addition, they are important to monitor for safe surface and sub-surface marine operations.

Reference:
The study, titled "Advanced Remote Sensing of Internal Waves by Spaceborne Along-Track InSAR—A Demonstration With TerraSAR-X," appears in the Dec. 2015 issue of the journal Transactions on Geoscience and Remote Sensing, a publication of the Institute of Electronic and Electrical Engineers (IEEE). DOI: 10.1109/TGRS.2015.2447547.

Note: The above post is reprinted from materials provided by University of Miami.

[jamesbond]

buti na lang at may study na ganyan for safe monitoring purposes not only for the nearby ocean dwellers but for the marine life as well.... 

[lovemarie]

Landslides and tsunamis under investigation on Australia's east coast

Three-dimensional numerical simulation of a tsunamigenic landslide event.

Credit: Museum fuer Naturkunde, Berlin


Australia’s coastline may be vulnerable to rare landslides with potentially disastrous consequences, according to ongoing research by the University of Sydney.

Undertaken by the University’s School of Geosciences, the research is detailed in a chapter in Southern Surveyor: Stories from on board Australia’s ocean research vessel, a new book from CSIRO Publishing. 

It’s hard to understand how these slopes ever fail yet the evidence is they can, because there are enormous scars, or scoops, along the continental margin from Bateman’s Bay to Fraser Island,” said Associate Professor Tom Hubble, lead researcher on the project.

“One of the largest examples of these continental scars is located off Bulli in New South Wales, and is 16 kilometres long, nine kilometres wide and roughly 300 to 400 metres thick.”

Importantly, the landslide events and the earthquakes that could trigger them are considered to be extremely rare, according to Associate Professor Hubble and his team.

“You might get one landslide every 10,000 years that could generate a wave of more than five metres in height. A wave height of more than 20 metres would only occur every 100,000 or even every million years.

“The big questions for us are how many, how big and how often? And we’re making some progress on this.

“We have actually identified 400 landslides that have occurred over the last 4 million years that are big enough to have generated a tsunami, most of which would have generated a tsunami with a one to two metre wave height.

“Around 50 to 100 of these could have generated something around five to 10 metres in wave height, which is the size of the tsunamis that came through Indonesia and Japan.

“We need to do more investigation to constrain these numbers reliably.”

Researchers believe the landslides could be triggered by large earthquakes, likely of magnitude six to seven, and are now investigating this theory.

“We are interested in conducting further studies in a section referred to as ‘the Block’ near Brisbane, which is about half a kilometre thick and 10 kilometres long, and has noticeable tension cracks.

“If an earthquake of the right magnitude occurred, we believe it could trigger a significant tsunami,” Associate Professor Hubble said.

Understanding these scoops and their potential sites, as well as their tsunami generating capabilities, has so far been restricted by the sonar technology on board the vessel Southern Surveyor, which could only map the sea floor to 3000 metres. The continental slope begins about 50 kilometres off the Australian coast and drops away to the abyssal plain, which is 4000 to 5000 metres deep.

Southern Surveyor: Stories from on board Australia’s ocean research vessel follows the adventures of the men and women on board the CSIRO Marine National Facility research vessel over the course of a year, as told by author Michael Veitch.

For 10 years, the Southern Surveyor represented the vanguard of Australian blue water marine science. On more than 100 voyages, this former North Sea fishing trawler with her distinctive blue and white livery carried scientists and technicians across the Southern, Pacific and Indian Oceans as well as the waters off northern Australia.

Note: The above post is reprinted from materials provided by University of Sydney.

[Heathcliff]

. . . . it is probably the after effect of underwater erosion that caused those coastal sinkholes.

here's another article concerning sinkholes in Australia...

~~~


The Inskip Sinkhole

The Inskip Sinkhole, as described in various media reports, developed on the Inskip Peninsular at MV Beagle Point, north of Rainbow Beach, on Saturday night:-



.

Descriptions of the event sound quite exciting, with a caravan, a trailer a car and some tents disappearing into the sea.  Fortunately there was no loss of life.  The best gallery of images of the aftermath can be found on the Sunshine Daily Coast website, from which this image is taken:



In the last couple of days the media have realised that this is not in fact a sinkhole, but is undoubtedly a submarine landslide. 

A Queensland Parks and Wildlife spokeswoman said the event was unlikely to be related to or caused by earthquake activity.  “Rather, it’s most likely a natural phenomenon caused by the undermining of part of the shoreline by rapid tidal flow, waves and currents,” she said.  “When this occurs below the waterline, the shoreline loses support and a section slides seaward, leaving a hole, the edges of which retrogress back towards the shore.”

It would be fascinating to see some high resolution bathymetry data for this area as these slope failure events should leave a very distinctive deposit on the seabed.  The above report quotes a local geologist, Ted Griffin, in explaining the phenomena:

“He said a large channel between Inskip Pt and Fraser Island regularly builds up a “shoulder” of sand, and falls away.  “This is a big channel, perhaps 50 or 100 metres. It’s just a very unstable cliff of sand,” he said.  “It seems to me very poor planning, that they’ve allowed development so close to such a vulnerable area.”

However, the exact mechanism of failure, and its causes, are not yet determined and would be worthy of further investigation.

...credits to the American Geophysical Union Blogs.