Satellites capable of finding fossils from space

3 Jan. () –

Multispectral satellite images are already capable of helping paleontologists to detect promising fossil beds before going into remote places.

New research from the laboratory of paleontologist Edward Davis of the University of Oregon Department of Earth Sciences shows that satellite data can reveal large individual fossils from the air, allowing field researchers to embark on deeper searches. specific on the ground.

Their findings were published in the journal Geological Magazine.

“Organizing field work is very expensive and carries many security risks,” he explains. it’s a statement Elena Ghezzo, who led the work as a postdoctoral researcher in the Davis lab. “So any additional information that can be obtained on the ground before you go is helpful. My method seems to be very good at ruling out regions that have no fossils.”

The team analyzed multispectral satellite images, which include not only visible light, but also other wavelengths such as ultraviolet and infrared. By looking at how the landscape absorbs or reflects all of these types of light, researchers can distinguish particular features, such as fossils, from the background.

This type of satellite data is often used to conduct aerial surveys of cities and track land use patterns. But until now it had not been used to search for specific fossilsexplains Ghezzo.

The researchers tested their idea with data from Arizona’s Petrified Forest National Park.

More than 200 million years ago, this landscape was a lush coniferous forest. Today it is a colorful desert dotted with fossilized logs. Based on a reference map they created by hand, the researchers they were able to identify signatures in the satellite data that distinguished a fossil from the background or from other landscape features.

To be detected by satellite, a fossil must be larger than a single pixel on the image. And its mineral composition must respond to light differently than the surrounding material. It’s easier when the landscape is flat and open, with relatively few obstacles, as it is in the Petrified Forest. But other data on the geology and topography of the region can also be taken into account, to help researchers distinguish a fossil from, say, a tree or a large rock.

Ghezzo collaborated with the Davis lab through a Marie Sklodowska-Curie Global Fellowship, an award that funds first-time researchers from European institutions to carry out independent research projects abroad. Now he is testing the technique in various fossil beds around the world, from Peru to Egypt and Mongolia.

And closer to home, Davis is especially interested in applying the method to some of his team’s sites in eastern Oregon.

In much of eastern Oregon, fossils are scattered over vast, remote tracts. Some areas, such as the John Day Fossil Beds, are declared natural areas. Motorized vehicles are prohibited, so fossils must be found on foot.

“There are a lot of places in inland Oregon that are very difficult to access even today,” Davis said. “Having the ability to use aerial photography to find fossils could help us allocate our resources.”

On a larger scale, such a technique could be part of a shift within the field of paleontology. Past practices, including blasting hillsides with dynamite, have irreparably damaged the landscape in some cases. A new generation of paleontologists works to make this field more sustainable and preserve the context in which the fossils are found.

“We don’t dig much anymore,” Davis states. Instead, researchers often wait for the fossils to be exposed by erosion and then excavate more selectively. And satellite data can help them.