Scientists find ancient mountains that fed early life

This image shows the ancient mountain site, Brazil. -  Carlos Ganade de Araujo
This image shows the ancient mountain site, Brazil. – Carlos Ganade de Araujo

Scientists have found evidence for a huge mountain range that sustained an explosion of life on Earth 600 million years ago.

The mountain range was similar in scale to the Himalayas and spanned at least 2,500 kilometres of modern west Africa and northeast Brazil, which at that time were part of the supercontinent Gondwana.

“Just like the Himalayas, this range was eroded intensely because it was so huge. As the sediments washed into the oceans they provided the perfect nutrients for life to flourish,” said Professor Daniela Rubatto of the Research School of Earth Sciences at The Australian National University (ANU).

“Scientists have speculated that such a large mountain range must have been feeding the oceans because of the way life thrived and ocean chemistry changed at this time, and finally we have found it.”

The discovery is earliest evidence of Himalayan-scale mountains on Earth.

“Although the mountains have long since washed away, rocks from their roots told the story of the ancient mountain range’s grandeur,” said co-researcher Professor Joerg Hermann.

“The range was formed by two continents colliding. During this collision, rocks from the crust were pushed around 100 kilometres deep into the mantle, where the high temperatures and pressures formed new minerals.”

As the mountains eroded, the roots came back up to the surface, to be collected in Togo, Mali and northeast Brazil, by Brazilian co-researcher Carlos Ganade de Araujo, from the University of Sao Paolo.

Dr Ganade de Araujo recognised the samples were unique and brought the rocks to ANU where, using world-leading equipment, the research team accurately identified that the rocks were of similar age, and had been formed at similar, great depths.

The research team involved specialists from a range of different areas of Earth Science sharing their knowledge, said Professor Rubatto.

“With everyone cooperating to study tiny crystals, we have managed to discover a huge mountain range,” she said.




Video
Click on this image to view the .mp4 video
Scientists from Australian National University reveal how they found a mountain range that fed an explosion of life 600 million years ago. The range stretched 2,500 km across Gondwana from modern west Africa to Northeast Brazil. Tiny mineral crystals formed in the roots of these huge mountains were the key to reconstructing their age and size. – ANU Media

Rivers flow differently over gravel beds, study finds

River researchers used a specially constructed model to study how water flows over gravel river beds. Illinois postdoctoral researcher Gianluca Blois (left) and professor Jim Best also developed a technique to measure the water flow between the pore spaces in the river bed. -  L. Brian Stauffer
River researchers used a specially constructed model to study how water flows over gravel river beds. Illinois postdoctoral researcher Gianluca Blois (left) and professor Jim Best also developed a technique to measure the water flow between the pore spaces in the river bed. – L. Brian Stauffer

River beds, where flowing water meets silt, sand and gravel, are critical ecological zones. Yet how water flows in a river with a gravel bed is very different from the traditional model of a sandy river bed, according to a new study that compares their fluid dynamics.

The findings establish new parameters for river modeling that better represent reality, with implications for field researchers and water resource managers.

“The shallow zones where water in rivers interacts with the subsurface are critical environmentally, and how we have modeled those in the past may be radically different from reality,” said Jim Best, a professor of geology, geography and geographic information science at the University of Illinois. “If you’re a river engineer or a geomorphologist or a freshwater biologist, predicting where and when sediment transport is going to occur is very important. This study provides us with a very different set of conditions to look at those environments and potentially manage them.”

Best and postdoctoral researcher Gianluca Blois led the study at the U. of I., in collaboration with colleagues in the United Kingdom. The team published its findings in the journal Geophysical Research Letters.

The researchers used a specially constructed flume in the Ven Te Chow Hydrosystems Laboratory at Illinois to experimentally compare scenarios ranging from the traditional model of an impermeable river bottom to a completely permeable river bed – a collection of spheres that simulate gravel.

The researchers used a technique called particle image velocimetry (PIV), a widely used method for quantifying how water flows over a model river bed, pioneered at the U. of I. in the 1980s. Best and Blois developed a method to use PIV endoscopically to study, for the first time, fluid flow within the small spaces between the gravel. This allowed them to quantify flow within the river bed and link it to the stream flow above.

They found that, in the scenario that simulates a gravel bed, the patterns of flow velocity above the bed and the distribution of forces on the river bed were dramatically different from the models on which all previous work has been based. Their experimental scenarios also disproved one popular theory that explained the difference between classic models and field observations for the formation of bed topography, such as dunes.

“Bedforms formed in fine sediments are known to be substantially different from those formed in gravel beds, but we just didn’t know why,” Blois said. “People before us suggested that those differences were due to the roughness of the grains. But we introduced the bed permeability, just like real rivers. This, with our new measurement technique, allowed us to demonstrate that most of the stress variation is actually coming from fluid emerging from the permeable bed, rather than roughness.”

The maps of water flow that the experiments produced could lead to better predictive models, so that researchers can more accurately predict and study how nutrients and pollutants travel and accumulate in rivers. These new models also could provide insight into the growth and behavior of organisms that thrive in the narrow zone where river flow meets the river bed.

“For example, when salmon spawn in gravel-bed rivers, they basically make a depression in the gravel, into which they lay their eggs,” Best said. “By doing that, not only do they protect the eggs, but they create a bump in the sediment that creates a pressure distribution that would keep fine grains from going into the bed, which would be detrimental to the eggs. It’s fascinating that fish actually take advantage of these flow dynamics.”

The researchers are working with collaborators around the world to study how permeability affects turbulence above the bed, how this affects the organisms that grow in the pore spaces, and how tiny particles and dissolved substances accumulate in porous riverbeds.

“It’s going to change the way we conceptualize these systems and model them,” Blois said. “We’re trying to raise awareness of the fact that we are now able to measure the complex flow dynamics in these challenging environments, and that’s going to open up a new paradigm for river research.”

Scientists find ancient mountains that fed early life

This image shows the ancient mountain site, Brazil. -  Carlos Ganade de Araujo
This image shows the ancient mountain site, Brazil. – Carlos Ganade de Araujo

Scientists have found evidence for a huge mountain range that sustained an explosion of life on Earth 600 million years ago.

The mountain range was similar in scale to the Himalayas and spanned at least 2,500 kilometres of modern west Africa and northeast Brazil, which at that time were part of the supercontinent Gondwana.

“Just like the Himalayas, this range was eroded intensely because it was so huge. As the sediments washed into the oceans they provided the perfect nutrients for life to flourish,” said Professor Daniela Rubatto of the Research School of Earth Sciences at The Australian National University (ANU).

“Scientists have speculated that such a large mountain range must have been feeding the oceans because of the way life thrived and ocean chemistry changed at this time, and finally we have found it.”

The discovery is earliest evidence of Himalayan-scale mountains on Earth.

“Although the mountains have long since washed away, rocks from their roots told the story of the ancient mountain range’s grandeur,” said co-researcher Professor Joerg Hermann.

“The range was formed by two continents colliding. During this collision, rocks from the crust were pushed around 100 kilometres deep into the mantle, where the high temperatures and pressures formed new minerals.”

As the mountains eroded, the roots came back up to the surface, to be collected in Togo, Mali and northeast Brazil, by Brazilian co-researcher Carlos Ganade de Araujo, from the University of Sao Paolo.

Dr Ganade de Araujo recognised the samples were unique and brought the rocks to ANU where, using world-leading equipment, the research team accurately identified that the rocks were of similar age, and had been formed at similar, great depths.

The research team involved specialists from a range of different areas of Earth Science sharing their knowledge, said Professor Rubatto.

“With everyone cooperating to study tiny crystals, we have managed to discover a huge mountain range,” she said.




Video
Click on this image to view the .mp4 video
Scientists from Australian National University reveal how they found a mountain range that fed an explosion of life 600 million years ago. The range stretched 2,500 km across Gondwana from modern west Africa to Northeast Brazil. Tiny mineral crystals formed in the roots of these huge mountains were the key to reconstructing their age and size. – ANU Media

Rivers flow differently over gravel beds, study finds

River researchers used a specially constructed model to study how water flows over gravel river beds. Illinois postdoctoral researcher Gianluca Blois (left) and professor Jim Best also developed a technique to measure the water flow between the pore spaces in the river bed. -  L. Brian Stauffer
River researchers used a specially constructed model to study how water flows over gravel river beds. Illinois postdoctoral researcher Gianluca Blois (left) and professor Jim Best also developed a technique to measure the water flow between the pore spaces in the river bed. – L. Brian Stauffer

River beds, where flowing water meets silt, sand and gravel, are critical ecological zones. Yet how water flows in a river with a gravel bed is very different from the traditional model of a sandy river bed, according to a new study that compares their fluid dynamics.

The findings establish new parameters for river modeling that better represent reality, with implications for field researchers and water resource managers.

“The shallow zones where water in rivers interacts with the subsurface are critical environmentally, and how we have modeled those in the past may be radically different from reality,” said Jim Best, a professor of geology, geography and geographic information science at the University of Illinois. “If you’re a river engineer or a geomorphologist or a freshwater biologist, predicting where and when sediment transport is going to occur is very important. This study provides us with a very different set of conditions to look at those environments and potentially manage them.”

Best and postdoctoral researcher Gianluca Blois led the study at the U. of I., in collaboration with colleagues in the United Kingdom. The team published its findings in the journal Geophysical Research Letters.

The researchers used a specially constructed flume in the Ven Te Chow Hydrosystems Laboratory at Illinois to experimentally compare scenarios ranging from the traditional model of an impermeable river bottom to a completely permeable river bed – a collection of spheres that simulate gravel.

The researchers used a technique called particle image velocimetry (PIV), a widely used method for quantifying how water flows over a model river bed, pioneered at the U. of I. in the 1980s. Best and Blois developed a method to use PIV endoscopically to study, for the first time, fluid flow within the small spaces between the gravel. This allowed them to quantify flow within the river bed and link it to the stream flow above.

They found that, in the scenario that simulates a gravel bed, the patterns of flow velocity above the bed and the distribution of forces on the river bed were dramatically different from the models on which all previous work has been based. Their experimental scenarios also disproved one popular theory that explained the difference between classic models and field observations for the formation of bed topography, such as dunes.

“Bedforms formed in fine sediments are known to be substantially different from those formed in gravel beds, but we just didn’t know why,” Blois said. “People before us suggested that those differences were due to the roughness of the grains. But we introduced the bed permeability, just like real rivers. This, with our new measurement technique, allowed us to demonstrate that most of the stress variation is actually coming from fluid emerging from the permeable bed, rather than roughness.”

The maps of water flow that the experiments produced could lead to better predictive models, so that researchers can more accurately predict and study how nutrients and pollutants travel and accumulate in rivers. These new models also could provide insight into the growth and behavior of organisms that thrive in the narrow zone where river flow meets the river bed.

“For example, when salmon spawn in gravel-bed rivers, they basically make a depression in the gravel, into which they lay their eggs,” Best said. “By doing that, not only do they protect the eggs, but they create a bump in the sediment that creates a pressure distribution that would keep fine grains from going into the bed, which would be detrimental to the eggs. It’s fascinating that fish actually take advantage of these flow dynamics.”

The researchers are working with collaborators around the world to study how permeability affects turbulence above the bed, how this affects the organisms that grow in the pore spaces, and how tiny particles and dissolved substances accumulate in porous riverbeds.

“It’s going to change the way we conceptualize these systems and model them,” Blois said. “We’re trying to raise awareness of the fact that we are now able to measure the complex flow dynamics in these challenging environments, and that’s going to open up a new paradigm for river research.”

Researchers solve riddle of the rock pools

The rock goby can change both its color and brightness to match its background in just one minute. -  Alice Lown
The rock goby can change both its color and brightness to match its background in just one minute. – Alice Lown

Research from the University of Exeter has revealed that the rock goby (Gobius paganellus), an unassuming little fish commonly found in rock pools around Britain, southern Europe, and North Africa, is a master of camouflage and can rapidly change colour to conceal itself against its background.

Whether hiding from predators or from families hunting in rock pools, the rock goby can change both its colour and brightness to match its background in just one minute.

Dr Martin Stevens from the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall said: “Anyone who’s been rock pooling will probably have encountered rock gobies, and may even have thought they could see them change colour in buckets. Our research shows that this is the case and that rock gobies can rapidly tune their appearance to match their background.”

The researchers found that when gobies were photographed on a bright white or dark background, they could change their brightness accordingly. When photographed on coloured backgrounds they altered their colour, becoming either more red or blue.

Undertaking this rapid visual change should be a major advantage for the fish when trying to avoid predators. Gobies find themselves under intense predation pressure at low tide from birds and at high tide from larger fish. To remain concealed they must rapidly respond as they are pushed over many different backgrounds by tides and waves.

The researchers collected the gobies from Gyllyngvase beach in Falmouth, Cornwall then photographed them against different backgrounds over time to quantify the speed and extent of the colour change. The results show that the fish were capable of rapid visual change for concealment.

The colour change is driven by special cells in the fishes’ bodies called ‘chromatophores’. These are found in many animals and work to condense or spread pigments of different colour over the body, changing the appearance of the fish. This process is guided by the visual system of the goby when it moves onto a new background.

Studies of colour change for camouflage have previously been undertaken in animals including chameleons, cuttlefish, flatfish, and crabs, but rarely have studies directly quantified the changes in colour and brightness that occur, how fast this happens, and how they affect camouflage matching.

NASA study finds 1934 had worst drought of last thousand years

A new study using a reconstruction of North American drought history over the last 1,000 years found that the drought of 1934 was the driest and most widespread of the last millennium.

Using a tree-ring-based drought record from the years 1000 to 2005 and modern records, scientists from NASA and Lamont-Doherty Earth Observatory found the 1934 drought was 30 percent more severe than the runner-up drought (in 1580) and extended across 71.6 percent of western North America. For comparison, the average extent of the 2012 drought was 59.7 percent.

“It was the worst by a large margin, falling pretty far outside the normal range of variability that we see in the record,” said climate scientist Ben Cook at NASA’s Goddard Institute for Space Studies in New York. Cook is lead author of the study, which will publish in the Oct. 17 edition of Geophysical Research Letters.

Two sets of conditions led to the severity and extent of the 1934 drought. First, a high-pressure system in winter sat over the west coast of the United States and turned away wet weather – a pattern similar to that which occurred in the winter of 2013-14. Second, the spring of 1934 saw dust storms, caused by poor land management practices, suppress rainfall.

“In combination then, these two different phenomena managed to bring almost the entire nation into a drought at that time,” said co-author Richard Seager, professor at the Lamont-Doherty Earth Observatory of Columbia University in New York. “The fact that it was the worst of the millennium was probably in part because of the human role.”

According to the recent Fifth Assessment Report of the Intergovernmental Panel on Climate Change, or IPCC, climate change is likely to make droughts in North America worse, and the southwest in particular is expected to become significantly drier as are summers in the central plains. Looking back one thousand years in time is one way to get a handle on the natural variability of droughts so that scientists can tease out anthropogenic effects – such as the dust storms of 1934.

“We want to understand droughts of the past to understand to what extent climate change might make it more or less likely that those events occur in the future,” Cook said.

The abnormal high-pressure system is one lesson from the past that informs scientists’ understanding of the current severe drought in California and the western United States.

“What you saw during this last winter and during 1934, because of this high pressure in the atmosphere, is that all the wintertime storms that would normally come into places like California instead got steered much, much farther north,” Cook said. “It’s these wintertime storms that provide most of the moisture in California. So without getting that rainfall it led to a pretty severe drought.”

This type of high-pressure system is part of normal variation in the atmosphere, and whether or not it will appear in a given year is difficult to predict in computer models of the climate. Models are more attuned to droughts caused by La Niña’s colder sea surface temperatures in the Pacific Ocean, which likely triggered the multi-year Dust Bowl drought throughout the 1930s. In a normal La Niña year, the Pacific Northwest receives more rain than usual and the southwestern states typically dry out.

But a comparison of weather data to models looking at La Niña effects showed that the rain-blocking high-pressure system in the winter of 1933-34 overrode the effects of La Niña for the western states. This dried out areas from northern California to the Rockies that otherwise might have been wetter.

As winter ended, the high-pressure system shifted eastward, interfering with spring and summer rains that typically fall on the central plains. The dry conditions were exacerbated and spread even farther east by dust storms.

“We found that a lot of the drying that occurred in the spring time occurred downwind from where the dust storms originated,” Cook said, “suggesting that it’s actually the dust in the atmosphere that’s driving at least some of the drying in the spring and really allowing this drought event to spread upwards into the central plains.”

Dust clouds reflect sunlight and block solar energy from reaching the surface. That prevents evaporation that would otherwise help form rain clouds, meaning that the presence of the dust clouds themselves leads to less rain, Cook said.

“Previous work and this work offers some evidence that you need this dust feedback to explain the real anomalous nature of the Dust Bowl drought in 1934,” Cook said.

Dust storms like the ones in the 1930s aren’t a problem in North America today. The agricultural practices that gave rise to the Dust Bowl were replaced by those that minimize erosion. Still, agricultural producers need to pay attention to the changing climate and adapt accordingly, not forgetting the lessons of the past, said Seager. “The risk of severe mid-continental droughts is expected to go up over time, not down,” he said.

Researchers solve riddle of the rock pools

The rock goby can change both its color and brightness to match its background in just one minute. -  Alice Lown
The rock goby can change both its color and brightness to match its background in just one minute. – Alice Lown

Research from the University of Exeter has revealed that the rock goby (Gobius paganellus), an unassuming little fish commonly found in rock pools around Britain, southern Europe, and North Africa, is a master of camouflage and can rapidly change colour to conceal itself against its background.

Whether hiding from predators or from families hunting in rock pools, the rock goby can change both its colour and brightness to match its background in just one minute.

Dr Martin Stevens from the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall said: “Anyone who’s been rock pooling will probably have encountered rock gobies, and may even have thought they could see them change colour in buckets. Our research shows that this is the case and that rock gobies can rapidly tune their appearance to match their background.”

The researchers found that when gobies were photographed on a bright white or dark background, they could change their brightness accordingly. When photographed on coloured backgrounds they altered their colour, becoming either more red or blue.

Undertaking this rapid visual change should be a major advantage for the fish when trying to avoid predators. Gobies find themselves under intense predation pressure at low tide from birds and at high tide from larger fish. To remain concealed they must rapidly respond as they are pushed over many different backgrounds by tides and waves.

The researchers collected the gobies from Gyllyngvase beach in Falmouth, Cornwall then photographed them against different backgrounds over time to quantify the speed and extent of the colour change. The results show that the fish were capable of rapid visual change for concealment.

The colour change is driven by special cells in the fishes’ bodies called ‘chromatophores’. These are found in many animals and work to condense or spread pigments of different colour over the body, changing the appearance of the fish. This process is guided by the visual system of the goby when it moves onto a new background.

Studies of colour change for camouflage have previously been undertaken in animals including chameleons, cuttlefish, flatfish, and crabs, but rarely have studies directly quantified the changes in colour and brightness that occur, how fast this happens, and how they affect camouflage matching.

NASA study finds 1934 had worst drought of last thousand years

A new study using a reconstruction of North American drought history over the last 1,000 years found that the drought of 1934 was the driest and most widespread of the last millennium.

Using a tree-ring-based drought record from the years 1000 to 2005 and modern records, scientists from NASA and Lamont-Doherty Earth Observatory found the 1934 drought was 30 percent more severe than the runner-up drought (in 1580) and extended across 71.6 percent of western North America. For comparison, the average extent of the 2012 drought was 59.7 percent.

“It was the worst by a large margin, falling pretty far outside the normal range of variability that we see in the record,” said climate scientist Ben Cook at NASA’s Goddard Institute for Space Studies in New York. Cook is lead author of the study, which will publish in the Oct. 17 edition of Geophysical Research Letters.

Two sets of conditions led to the severity and extent of the 1934 drought. First, a high-pressure system in winter sat over the west coast of the United States and turned away wet weather – a pattern similar to that which occurred in the winter of 2013-14. Second, the spring of 1934 saw dust storms, caused by poor land management practices, suppress rainfall.

“In combination then, these two different phenomena managed to bring almost the entire nation into a drought at that time,” said co-author Richard Seager, professor at the Lamont-Doherty Earth Observatory of Columbia University in New York. “The fact that it was the worst of the millennium was probably in part because of the human role.”

According to the recent Fifth Assessment Report of the Intergovernmental Panel on Climate Change, or IPCC, climate change is likely to make droughts in North America worse, and the southwest in particular is expected to become significantly drier as are summers in the central plains. Looking back one thousand years in time is one way to get a handle on the natural variability of droughts so that scientists can tease out anthropogenic effects – such as the dust storms of 1934.

“We want to understand droughts of the past to understand to what extent climate change might make it more or less likely that those events occur in the future,” Cook said.

The abnormal high-pressure system is one lesson from the past that informs scientists’ understanding of the current severe drought in California and the western United States.

“What you saw during this last winter and during 1934, because of this high pressure in the atmosphere, is that all the wintertime storms that would normally come into places like California instead got steered much, much farther north,” Cook said. “It’s these wintertime storms that provide most of the moisture in California. So without getting that rainfall it led to a pretty severe drought.”

This type of high-pressure system is part of normal variation in the atmosphere, and whether or not it will appear in a given year is difficult to predict in computer models of the climate. Models are more attuned to droughts caused by La Niña’s colder sea surface temperatures in the Pacific Ocean, which likely triggered the multi-year Dust Bowl drought throughout the 1930s. In a normal La Niña year, the Pacific Northwest receives more rain than usual and the southwestern states typically dry out.

But a comparison of weather data to models looking at La Niña effects showed that the rain-blocking high-pressure system in the winter of 1933-34 overrode the effects of La Niña for the western states. This dried out areas from northern California to the Rockies that otherwise might have been wetter.

As winter ended, the high-pressure system shifted eastward, interfering with spring and summer rains that typically fall on the central plains. The dry conditions were exacerbated and spread even farther east by dust storms.

“We found that a lot of the drying that occurred in the spring time occurred downwind from where the dust storms originated,” Cook said, “suggesting that it’s actually the dust in the atmosphere that’s driving at least some of the drying in the spring and really allowing this drought event to spread upwards into the central plains.”

Dust clouds reflect sunlight and block solar energy from reaching the surface. That prevents evaporation that would otherwise help form rain clouds, meaning that the presence of the dust clouds themselves leads to less rain, Cook said.

“Previous work and this work offers some evidence that you need this dust feedback to explain the real anomalous nature of the Dust Bowl drought in 1934,” Cook said.

Dust storms like the ones in the 1930s aren’t a problem in North America today. The agricultural practices that gave rise to the Dust Bowl were replaced by those that minimize erosion. Still, agricultural producers need to pay attention to the changing climate and adapt accordingly, not forgetting the lessons of the past, said Seager. “The risk of severe mid-continental droughts is expected to go up over time, not down,” he said.

Researchers turn to 3-D technology to examine the formation of cliffband landscapes

This is a scene from the Colorado Plateau region of Utah. -  Dylan Ward
This is a scene from the Colorado Plateau region of Utah. – Dylan Ward

A blend of photos and technology takes a new twist on studying cliff landscapes and how they were formed. Dylan Ward, a University of Cincinnati assistant professor of geology, will present a case study on this unique technology application at The Geological Society of America’s Annual Meeting & Exposition. The meeting takes place Oct. 19-22, in Vancouver.

Ward is using a method called Structure-From-Motion Photogrammetry – computational photo image processing techniques – to study the formation of cliff landscapes in Colorado and Utah and to understand how the layered rock formations in the cliffs are affected by erosion.

To get an idea of these cliff formations, think of one of the nation’s most spectacular tourist attractions, the Grand Canyon.

“The Colorado plateau, for example, has areas with a very simple, sandstone-over-shale layered stratigraphy. We’re examining how the debris and sediment off that sandstone ends up down in the stream channels on the shale, and affects the erosion by those streams,” explains Ward. “The river cuts down through the rock, creating the cliffs. The cliffs walk back by erosion, so there’s this spectacular staircase of stratigraphy that owes its existence and form to that general process.”

Ward’s research takes a new approach to documenting the topography in very high resolution, using a new method of photogrammetry – measurement in 3-D, based on stereo photographs.

“First, we use a digital camera to take photos of the landscape from different angles. Then, we use a sophisticated imaging processing program than can take that set of photos and find the common points between the photographs. From there, we can build a 3-D computer model of that landscape. Months of fieldwork, in comparison, would only produce a fraction of the data that we produce in the computer model,” says Ward.

Ward says that ultimately, examining this piece of the puzzle will give researchers an idea as to how the broader U.S. landscape was formed.

Researchers turn to 3-D technology to examine the formation of cliffband landscapes

This is a scene from the Colorado Plateau region of Utah. -  Dylan Ward
This is a scene from the Colorado Plateau region of Utah. – Dylan Ward

A blend of photos and technology takes a new twist on studying cliff landscapes and how they were formed. Dylan Ward, a University of Cincinnati assistant professor of geology, will present a case study on this unique technology application at The Geological Society of America’s Annual Meeting & Exposition. The meeting takes place Oct. 19-22, in Vancouver.

Ward is using a method called Structure-From-Motion Photogrammetry – computational photo image processing techniques – to study the formation of cliff landscapes in Colorado and Utah and to understand how the layered rock formations in the cliffs are affected by erosion.

To get an idea of these cliff formations, think of one of the nation’s most spectacular tourist attractions, the Grand Canyon.

“The Colorado plateau, for example, has areas with a very simple, sandstone-over-shale layered stratigraphy. We’re examining how the debris and sediment off that sandstone ends up down in the stream channels on the shale, and affects the erosion by those streams,” explains Ward. “The river cuts down through the rock, creating the cliffs. The cliffs walk back by erosion, so there’s this spectacular staircase of stratigraphy that owes its existence and form to that general process.”

Ward’s research takes a new approach to documenting the topography in very high resolution, using a new method of photogrammetry – measurement in 3-D, based on stereo photographs.

“First, we use a digital camera to take photos of the landscape from different angles. Then, we use a sophisticated imaging processing program than can take that set of photos and find the common points between the photographs. From there, we can build a 3-D computer model of that landscape. Months of fieldwork, in comparison, would only produce a fraction of the data that we produce in the computer model,” says Ward.

Ward says that ultimately, examining this piece of the puzzle will give researchers an idea as to how the broader U.S. landscape was formed.