Study ties fracking to another type of shaking

Oil extraction practice triggers tremors

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - RIVERSIDE

 

IMAGE: SHALE GAS DRILLING (FRACKING) RIG NEAR ALVARADO, TEXAS. view more 

CREDIT: LOADMASTER (DAVID R. TRIBBLE)

New research confirms fracking causes slow, small earthquakes or tremors, whose origin was previously a mystery to scientists. The tremors are produced by the same processes that could create large, damaging earthquakes. 

Fracking is the high-pressure injection of fluids underground to extract oil and natural gas. Though it is typically done with wastewater, this study examined data from fracking with liquid carbon dioxide. The process pushes carbon underground and keeps it from trapping heat in Earth’s atmosphere.

By some estimates, carbon dioxide fracking could save as much carbon annually as one billion solar panels. It is much more advantageous for the environment to frack with liquid CO2 than with wastewater, which does not keep carbon out of the atmosphere.

“Because this study examines a process that sequesters carbon underground, there may be positive implications for sustainability, and for climate science,” said Abhijit Ghosh, associate professor of geophysics at UC Riverside and co-author of the study in the journal Science.

Because the carbon dioxide is liquid, however, Ghosh said the results of this study almost certainly apply to fracking with water. Both are likely to cause tremors. 

On a seismograph, regular earthquakes and tremors appear differently. Big quakes cause sharp jolts with high amplitude pulses. Tremors are more gentle, rising up slowly above the background noise with much less amplitude, and then slowly decreasing. 

“We are pleased that we are now able to use these tremors to track the movement of fluids from fracking and monitor the movement of faults resulting from the fluid injections,” Ghosh said. 

Previously, there was debate amongst seismologists about the source of the tremors. While some papers argued the tremor signals were from large earthquakes happening thousands of miles away, others thought they could have been noise generated by human activity, like the movement of trains or industrial machinery.

“Seismometers are not smart. You could drive a truck nearby, or kick one with your foot, and it would record that vibration,” Ghosh said. “That’s why for some time we didn’t know for sure if the signals were related to the fluid injections.”

To determine their origin, the researchers used seismometers installed around a fracking site in Wellington, Kansas. The data covered the entire fracking injection period of six months, as well as a month prior to the injections and a month following them. 

After discarding the background noise, the team showed that the remaining signals were generated below ground and only appeared while the fluid injections were occurring. “We did not detect the tremors before or after the injections, which suggests the tremors are related to them,” Ghosh said. 

It has been known for some time that fracking can produce larger earthquakes. To keep faults from slipping underground and producing them, or tremors, one option would be to stop fracking. As this is unlikely, Ghosh says it is important to monitor these activities to understand how rocks are being deformed by them, and to track the movement of fluids after injection.

Modeling experiments can be and are performed to help companies determine fluid injection pressures that should not be exceeded. Staying within these limits helps ensure that the fluids will not migrate towards large faults underground, triggering damaging seismic activity. However, not all faults are mapped. 

“We can only model this type of experiment when we know there is an existing fault. It is possible there are faults we do not know of, and in those cases, we cannot forecast what will happen,” Ghosh said. 

---

JOURNAL

Science

DOI

10.1126/science.adh1331 

ARTICLE TITLE

Tremor signals during fluid injection are generated by fault slip

 

Evolving elegance: TU Dresden scientists connect beauty and safeguarding in ammonoid shells

Peer-Reviewed Publication

TECHNISCHE UNIVERSITÄT DRESDEN

 

IMAGE: A KOSMOCERAS AMMONITE FOSSIL. A CT SCAN RENDER view more 

CREDIT: ROBERT LEMANIS

Ammonoids are a group of extinct marine mollusk animals that are now an iconic fossil group often collected by amateurs. Over 350 million years of evolution, ammonoids developed increasingly elaborate shells with fractal-like geometry. For nearly 200 years, scientists have debated the reason why these animals show a trend of increasing complexity in their shell structures. Dr. Robert Lemanis and Dr. Igor Zlotnikov from the B CUBE – Center for Molecular Bioengineering at TU Dresden created mechanical simulations of theoretical and computed tomography-based models to unveil a potential explanation: the intricate architecture of these shells may have been nature's ingenious defense strategy against a wide array of predators.

“Over the course of 350 million years of evolution, ammonoids repeatedly evolved shells with increasingly complex inner walls. The persistence and repetitiveness of this trend imply some driving force; the question that has long remained unanswered is: what driving force? Opposition to water pressure, muscle attachments, respiration, Cartesian devils. All of these have been proposed as explanations for this trend but evidence for them is scarce. So we decided to explore a neglected idea,” explains Dr. Robert Lemanis, researcher in Dr. Zlotnikov’s group at the B CUBE.

The team's findings propose a fascinating correlation between the evolving complexity of the ammonoid shell and its resilience against external forces. As these ancient creatures roamed the oceans, their shells shielded them against predators and other environmental factors. The intricate inner structures provided crucial reinforcement, making it progressively harder for predators to crack them.

“Consider that the ammonoid shell was a relatively thin structure and once it was fractured, the animal could not repair it. A robust shell – one that can resist the damage – provided higher chances of survival,” explains Dr. Lemanis.

In essence, the shell's evolution could be a story of survival against the odds. Through countless years of adaptation and innovation, these ancient creatures crafted their defenses with remarkable precision. This new insight from the B CUBE researchers offers us a glimpse into the distant past, where the beauty of nature intertwines with the relentless pressures of survival.

“Our work bridges biology and engineering, underscoring how animals harness the power of fractal morphology to design more robust biomaterials. It can provide inspiration for resilient structural designs,” summarizes Dr. Zlotnikov, research group leader at the B CUBE.

Original Publication
Robert Lemanis, Igor Zlotnikov: Fractal-like geometry as an evolutionary response to predation? Science Advances
Link: https://doi.org/10.1126/sciadv.adh0480

About B CUBE
B CUBE – Center for Molecular Bioengineering was founded as a Center for Innovation Competence within the initiative “Unternehmen Region” of the German Federal Ministry of Education and Research. It is part of the Center for Molecular and Cellular Bioengineering (CMCB). B CUBE research focuses on the investigation of living structures on a molecular level, translating the ensuing knowledge into innovative methods, materials and technologies.
Web: www.tu-dresden.de/cmcb/bcube

Resources:
Website of the research group of Dr. Igor Zlotnikov: https://tud.link/xnfz
High-resolution photos: https://tud.link/w1cy

---

JOURNAL

Science Advances

DOI

10.1126/sciadv.adh0480 

ARTICLE TITLE

Fractal-like geometry as an evolutionary response to predation?

Tiny “ice mouse” survived Arctic cold in the age of dinosaurs

Peer-Reviewed Publication

UNIVERSITY OF COLORADO AT BOULDER

 

IMAGE: A TEAM OF PALEONTOLOGISTS DIGS ALONG THE BANKS OF THE COLVILLE RIVER IN NORTHERN ALASKA. view more 

CREDIT: KEVIN MAY

Paleontologists working in northern Alaska have discovered a tiny fossil mammal that thrived in what may have been among the coldest conditions on Earth about 73 million years ago.

The researchers, led by Jaelyn Eberle of the University of Colorado Boulder, described the Late Cretaceous animal in a study published this month in the Journal of Systematic Palaeontology.

They gave it the scientific name Sikuomys mikros—from “Siku,” an Iñupiaq word for “ice,” and “mys” and “mikros,” the Greek words for “mouse” and “little.”

It’s a fitting title. While the little ice mouse wasn’t actually a mouse, instead belonging to a now-extinct family of mammals called Gypsonictopidae, it was certainly tiny. The furry critter may have looked a bit like a modern-day shrew and weighed an estimated 11 grams, or less than an empty aluminum soda can. It also lived year-round in northern Alaska, which at the time lay much farther north, above the planet’s Arctic Circle. There, the ice mouse likely weathered as much as four months of unending darkness in the winter and temperatures that fell below freezing.

“These guys probably didn’t hibernate,” said Eberle, curator of fossil vertebrates at the CU Museum of Natural History and professor in the Department of Geological Sciences. “They stayed active all year long, burrowing under leaf litter or underground and feeding on whatever they could sink their teeth into, probably insects and worms.”

She and her colleagues had to be equally tenacious to discover the fossil animals: The researchers identified the new species from only a handful of tiny teeth, each about the size of a grain of sand.

“I always like working at the ends of the Earth,” Eberle said. “You never know what you’re going to find, but you know it’s going to be new.”

Those minute fossils are giving researchers a new window into ancient Alaska, said study co-author Patrick Druckenmiller, director of the University of Alaska Museum of the North. 

“Seventy-three million years ago, northern Alaska was home to an ecosystem unlike any on Earth today,” he said. “It was a polar forest teeming with dinosaurs, small mammals and birds. These animals were adapted to exist in a highly seasonal climate that included freezing winter conditions, likely snow and up to four months of complete winter darkness.” 

Venturing north

Getting to the ends of the Earth isn’t always easy.

The researchers, including paleontologists from the University of Alaska Fairbanks and Florida State University, unearthed the fossils from sediments along the banks of the Colville River—not far from the Beaufort Sea on Alaska’s northern coast. The site, part of what's called the Prince Creek Formation, is so remote the team travels the 75 or so miles from Deadhorse, Alaska, by snowmobile or bush plane. 

“Our team's research is revealing a ‘Lost world’ of Arctic-adapted animals,” said Gregory Erickson, a co-author of the study at Florida State University. “Prince Creek serves as a natural test of these animal's physiology and behavior in the face of drastic seasonal climatic fluctuations.”

The late William Clemens of the University of California, Berkeley was also a co-author of the new research.

Unlike dinosaurs from the same time period, which left behind large bones, the only fossils remaining from the region’s mammals are a few teeth and fragments of jaws. To recover these precious specimens, the group collects buckets of dirt from the riverbanks. In the lab, the researchers wash away the mud and sort what remains under a microscope.

“You look under the microscope and see this perfect little tooth,” Eberle said. “It’s so tiny.” 

Safety underground

In the case of the ice mouse, those perfect little teeth have inspired a perfect little mystery.

For many groups of mammals on Earth, species tend to get bigger at higher latitudes and cooler climates. The ice mouse and its close cousins seem to follow the opposite pattern. Paleontologists have found related species living thousands of miles to the south that were three to five times larger than Sikuomys mikros.

Eberle suspects the ice mouse was so small because there was so little to eat during the winter in Alaska.

“We see something similar in shrews today,” she said. “The idea is that if you’re really small, you have lower food and energy needs.”

Sikuomys mikros may have spent the cold months in Alaska underground. In the end, such a subterranean lifestyle may have been a blessing for animals like the ice mouse. Burrowing mammals may have stood a better chance of surviving the harsh conditions that followed the meteorite crash that killed the dinosaurs 66 million years ago.

A fossilized Sikuomys mikros tooth about the size of a grain of sand seen under the microscope.

JP Cavigelli of the Tate Geological Museum in Wyoming holds up a tiny mammal tooth.

CREDIT

Jaelyn Eberle

JOURNAL

Journal of Systematic Palaeontology

DOI

10.1080/14772019.2023.2232359 

ARTICLE TITLE

A new tiny eutherian from the Late Cretaceous of Alaska

Unveiling the tale of Tutcetus, the pharaoh of whales who died young 41 million years ago

Discovering a new species of an extinct whale, that inhabited the ancient sea covering present-day Egypt around 41 million years ago

Peer-Reviewed Publication

MANSOURA UNIVERSITY VERTEBRATE PALEONTOLOGY CENTER (MUVP)

 

IMAGE: THE EGYPTIAN PALEONTOLOGISTS ABDULLAH GOHAR, MOHAMED SAMEH, AND HESHAM SALLAM (FROM LEFT) NEXT TO THE HOLOTYPE FOSSILS OF THE NEWLY IDENTIFIED BASILOSAURID WHALE, TUTCETUS RAYANENSIS, AT MANSOURA UNIVERSITY VERTEBRATE PALEONTOLOGY CENTER. view more 

CREDIT: HESHAM SALLAM - MANSOURA UNIVERSITY VERTEBRATE PALEONTOLOGY CENTER

An international team of scientists, led by Egyptian researchers, has made a groundbreaking discovery of a new species of extinct whale, Tutcetus rayanensis, that inhabited the ancient sea covering present-day Egypt around 41 million years ago. This new whale is the smallest basilosaurid whale known to date and one of the oldest records of that family from Africa. Despite its tiny size, Tutcetus has provided unprecedented insights into the life history, phylogeny, and paleobiogeography of early whales.

Basilosauridae, a group of extinct fully aquatic whales, represents a crucial stage in whale evolution, as they transitioned from land to sea. They developed fish-like characteristics, such as a streamlined body, a strong tail, flippers, and a tail fin, and had the last hind limbs visible enough to be recognized as “legs”, which were not used for walking but possibly for mating.

The newly discovered Tutcetus rayanensis was found in the middle Eocene rocks and unambiguously, it helps to illuminate the picture of early whale evolution in Africa. The new whale’s name draws inspiration from both Egyptian history and the location where the specimen was found. The genus name, Tutcetus, combines "Tut" – referring to the famous Egyptian Pharaoh Tutankhamun – and "cetus," Greek for whale, highlighting the specimen's small size and subadult status. The name also commemorates the discovery of the king's tomb a century ago and coincides with the impending opening of the Grand Egyptian Museum in Giza. The species name, rayanensis, refers to the Wadi El-Rayan Protected Area in Fayum where the holotype was found.

Hesham Sallam, a Professor of Vertebrate Paleontology at the American University in Cairo, founder of Mansoura University Vertebrate Paleontology Center, and the leader of the project, commented that: "Whales’ evolution from land-dwelling animals to beautiful marine creatures embodies the marvelous adventurous journey of life”. He continued: “Tutcetus is a remarkable discovery that documents one of the first phases of the transition to a fully aquatic lifestyle that took place in that journey”.

The holotype specimen consists of a skull, jaws, hyoid bone, and the atlas vertebra of a small-sized subadult basilosaurid whale which is embedded in an intensively compacted limestone block. With an estimated length of 2.5 meters and a body mass of approximately 187 kilograms, Tutcetus is the smallest known basilosaurid to date. 

The team's findings have been published in Communications Biology, and the lead author, Mohammed Antar, from the Mansoura University Vertebrate Paleontology Center, and the National Focal Point for Natural Heritage stated that: "Tutcetus significantly broadens the size range of basilosaurid whales and reveals considerable disparity among whales during the middle Eocene period”. Antar added: “The investigation of the older layers in Fayum layers may reveal the existence of an older assemblage of early whale fossils, potentially influencing our current knowledge of the emergence and dispersal of whales”. 

Sanaa El-Sayed, a PhD student at University of Michigan and a member of Sallam Lab, and a co-author of the study stated that: “The relatively small size of Tutcetus (188 kg) is either primitive retention or could be linked to the global warming event known as the "Late Lutetian Thermal Maximum (LLTM)”. El-Sayed added: “This groundbreaking discovery sheds light on the early evolution of whales and their transition to aquatic life”.

Through detailed analyses of Tutcetus's teeth and bones, using CT scanning, the team was able to reconstruct the growth and development pattern of this species, providing an unparalleled understanding of the life history of early whales. The rapid dental development and small size of Tutcetus suggest a precocial lifestyle with a fast pace of life history for early whales. Additionally, the discovery of Tutcetus contributes to the understanding of the basilosaurids' early success in the aquatic environment, their capacity to outcompete amphibious stem whales, and their ability to opportunistically adapt to new niches after severing their ties to the land. The team's findings suggest that this transition likely occurred in the (sub)tropics.

Abdullah Gohar, a PhD student at Mansoura University and a member of Sallam Lab and a co-author of the study, stated that: “Modern whales migrate to warmer, shallow waters for breeding and reproduction, mirroring the conditions found in Egypt 41 million years ago. This supports the idea that what is known as now Fayum was a crucial breeding area for ancient whales, possibly attracting them from various locations and, in turn, drawing in larger predatory whales like Basilosaurus”.

The team's findings have significant paleobiogeographic implications, demonstrating that basilosaurids likely achieved a rapid spread over the Southern Hemisphere, reaching high latitudes by the middle Eocene. 

Erik Seiffert, who is the Chair and Professor of Integrative Anatomical Sciences at the University of Southern California and a co-author of the study, remarked, "The Eocene fossil sites of Egypt’s Western Desert have long been the world’s most important for understanding the early evolution of whales and their transition to a fully aquatic existence”. Seiffert added: “The discovery of Tutcetus demonstrates that this region still has so much more to tell us about the fascinating story of whale evolution".

  

Life reconstruction of the extinct basilosaurid whale Tutcetus rayanensis swimming in the Tethys Ocean of present-day Egypt, 41 million years ago. Illustration by Ahmed Morsi.

Life reconstruction of two individuals of the extinct basilosaurid whale Tutcetus rayanensis, with the foreground individual preying on a nautilid cephalopod and another swimming in the background. Illustration by Ahmed Morsi.

Egyptian researchers don the regalia of King Tutankhamun as they proudly present the holotype fossils of the newly discovered whale species, Tutcetus rayanensis, at Mansoura University Vertebrate Paleontology Center. From left: Abdullah Gohar holds the symbolic crook and flail of King Tutankhamun, Mohamed Sameh wears the iconic King Tutankhamun Scarab Necklace, and Hesham Sallam sports Tutankhamun’s Scarab Bracelet.

CREDIT

Hesham Sallam - Mansoura University Vertebrate Paleontology Center

JOURNAL

Communications Biology

DOI

10.1038/s42003-023-04986-w 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

A diminutive new basilosaurid whale reveals the trajectory of the cetacean life histories during the Eocene

ARTICLE PUBLICATION DATE

10-Aug-2023

http://prehistoricpulp.blogspot.com/2007/09/ice-hunt-by-james-rollins-2003.html

Ice Hunt by James Rollins (2003) - Prehistoric Pulp 

Sep 5, 2007 ... Ice Hunt starts when an experimental U.S. Navy submarine finds an abandoned military base carved into the side of an iceberg in the Arctic Ocean ...

Google Ads algorithm misses Spanish speakers for SNAP benefits

Reports and Proceedings

CORNELL UNIVERSITY

ITHACA, N.Y. – A Cornell University-led research team has discovered that the algorithm behind Google Ads charged significantly more to deliver online ads to Spanish-speaking people in California about the benefits of SNAP, formerly known as food stamps.

“SNAP is a really important resource to get right,” said Allison Koenecke, lead author of the study and assistant professor of information science. “When faced with an algorithm that has disparate impact, our research asks, how do you pick a strategy to interact with the algorithm to equitably recruit SNAP applicants?”

Californians can apply for SNAP benefits using a website called GetCalFresh, which is developed and managed by Code for America, a civic tech nonprofit that builds digital tools and services for community leaders and governments. Code for America primarily recruits GetCalFresh applicants through Google Ads – for example, spending roughly $400 daily to reach anyone from San Diego County who punches key words and phrases like “how to apply for food stamps” into Google.

However, despite GetCalFresh being offered in multiple languages, Spanish-speakers were filling out proportionally fewer applications than English-speakers. In San Diego County, 23% of families living below the poverty line speak Spanish as their primary language, and yet just 7% had applied for SNAP via GetCalFresh, researchers said.

Koenecke and her collaborators discovered one possible reason: the default, dollar-stretching algorithm behind Google Ads was working too efficiently and disregarding Spanish-speaking people in the process.

When Google Ads is configured to garner the most SNAP enrollments per dollar, it ends up delivering fewer ads to prospective Spanish-speaking applicants because such ads cost more than those for English speakers, the team found. At the time, for every $1 spent on Google Ads to “convert” an English-speaking applicant into a SNAP benefits holder, it cost $3.80 to convert a Spanish-speaking person – nearly four times more. Another bidding option on the Google Ads platform cost 1.4 times more to reach Spanish-speakers versus English-speakers.

Koenecke and her collaborators can’t definitively explain the difference, since Google Ads is a black box – a proprietary machine-learning tool outside of public review. It could be attributed to any number of factors, like supply and demand or a bug in the system, she said.

For GetCalFresh, the research findings pose an important ethical question regarding how to spend its limited online advertising budget: Should they reach as many Californians as cheaply as possible, even if that means fewer Spanish-speaking applicants, or advertise more to Spanish-speakers, even if that yields fewer total applicants?

Trade-offs such as these are at the heart of Koenecke’s research into fairness and algorithmic systems, which are increasingly being used to help with decision-making in areas with real consequences, like health care, banking and child services. But without additional scrutiny, algorithms – including a seemingly harmless one behind an advertising platform – can exacerbate inequality or produce results that run counter to what people actually want or need, she said.

As a result of the team’s findings, Code for America adjusted its online advertising strategy to directly target more Spanish-speaking prospective applicants.

“It’s important for the field and the public to have productive dialogues about the kinds of metrics we should be using in these algorithmic systems,” she said. “The communities most impacted by the algorithms should be given more power in the decision-making process.”

This research was partly funded by the National Science Foundation and Stanford University.

For additional information, see this Cornell Chronicle story.

-30-

 

Could artificially dimming the sun prevent ice melt?

Peer-Reviewed Publication

UNIVERSITY OF BERN

With methods of so-called geoengineering, the climate could theoretically be artificially influenced and cooled. Bernese researchers have now investigated whether it would be possible to prevent the melting of the West Antarctic ice sheet by artificially "dimming the sun". The results show that artificial influence does not work without decarbonization and entails high risks.

Is there an emergency solution that could stop climate change? Technical methods that artificially influence the climate have been discussed for some time under the term geoengineering. However, the majority of climate researchers have been critical of them: high risks, incalculable consequences for future generations.

In a study just published in the journal Nature Climate Change, researchers led by Johannes Sutter of the Climate and Environmental Physics Division (KUP) at the Institute of Physics and the Oeschger Center for Climate Research at the University of Bern investigate the question of whether the melting of ice in West Antarctica could be prevented by artificially influencing solar radiation. The researchers also warn of unforeseeable side effects of geoengineering.

Avoiding a key climate tipping point

"The window of opportunity to limit the global temperature increase to below 2 degrees is closing fast," says ice modeling specialist Johannes Sutter, "so it is possible that technical measures to influence the climate will be seriously considered in the future." That is why, he says, it is necessary to use theoretical models to study the effects and risks of "solar radiation management." Solar Radiation Management (SRM) is a term used to describe various methods of blocking solar radiation in order to make the Earth cooler.

A key reason for the increased interest in geoengineering is the avoidance of tipping points at which the climate could change abruptly and irreversibly. These include the melting of the West Antarctic and Greenland ice sheets and the associated meter-high sea level rise. "Observations of ice flows in West Antarctica indicate that we are very close to a so-called tipping point or have already passed it," explains Johannes Sutter, "with our study, we therefore  wanted to find out  whether a collapse of the ice sheet could theoretically be prevented with solar radiation management."

Artificially dimming the sun

Specifically, Sutter and his colleagues have investigated what would happen if so-called aerosols – suspended particles in a gas – introduced into the stratosphere succeeded in blocking solar radiation from the earth – a dimming of the sun, so to speak. So far, research has focused on the global effects of solar radiation management (SRM). The Bern study is the first to use ice model simulations to show what effect such a measure would have on the Antarctic ice sheet. The study examines the possible development of the ice sheet under different future greenhouse gas scenarios and yields differentiated results: If emissions continue unabated and the SRM occurs in the middle of this century, the collapse of the West Antarctic Ice Sheet could be delayed somewhat, but not prevented. In a medium emissions scenario, SRM deployed by mid-century could prove to be an "effective tool" to slow or even prevent ice sheet collapse.

According to the model calculations, SRM works best when it occurs as early as possible and is combined with ambitious climate mitigation measures. But, the study authors emphasize, "our simulations show that the most effective way to prevent long-term collapse of the West Antarctic Ice Sheet is rapid decarbonization." The chances of a longer-term stable ice sheet are greatest if greenhouse gas emissions were reduced to net zero "without delay."

Possible side effects still hardly studied

But how should one imagine a dimming of the sun in practical terms? According to Johannes Sutter, a whole fleet of extremely high-flying airplanes would have to spread millions of tons of aerosols in the stratosphere. However, this technical intervention in the climate would have to be maintained without interruption and for centuries. If the intervention were stopped as long as the greenhouse concentration in the atmosphere remained high, the temperature on earth would quickly rise by several degrees.

The consequences of such a termination shock, Johannes Sutter points out, are only one of the possible dangers posed by SRM. The potential side effects are still insufficiently researched and range from a shift in the monsoon regime to changes in ocean and atmospheric circulation. Ocean acidification would also continue. Critical voices also caution political and social effects: The use of techniques such as solar dimming could lead to climate protection measures being slowed down or even prevented. Thomas Stocker, professor of climate and environmental physics at the University of Bern and co-author of the study, says: "Geoengineering would be another global experiment and a potentially dangerous human intervention in the climate system, which should in any case be prevented according to Article 2 of the UN Framework Convention on Climate Change."

Publication details:  

Climate intervention on high emission pathway could delay but not prevent West Antarctic Ice Sheet demise, J. Sutter, A. Jones, T. L. Frölicher, C. Wirths, T. F. Stocker, 10 August, 2023, Nature Climate Change.

doi: https://doi.org/10.1038/s41558-023-01738-w

Contacts:

Dr. Johannes Sutter

Oeschger Center for Climate Research at the University of Bern

Tel.: +41 31 684 4275

E-Mail: johannes.sutter@unibe.ch

 

Prof. Dr. Thomas Stocker

Oeschger Center for Climate Research at the University of Bern

Tel.: +41 31 684 44 62

E-Mail: thomas.stocker@unibe.ch

 

Oeschger-Zentrum for Climate Research The Oeschger Center for Climate Change Research (OCCR) is one of the strategic centers of the University of Bern. It brings together researchers from 14 institutes and four faculties. The OCCR conducts interdisciplinary research at the cutting edge of climate change research. The Oeschger Center was founded in 2007 and bears the name of Hans Oeschger (1927–1998), a pioneer of modern climate research, who worked in Bern.   Further information: www.oeschger.unibe.ch

---

JOURNAL

Nature Climate Change

DOI

10.1038/s41558-023-01738-w 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Climate intervention on high emission pathway could delay but not prevent West Antarctic Ice Sheet demise

ARTICLE PUBLICATION DATE

10-Aug-2023

 

New insights into the potential for early steps of biological evolution on Mars

Peer-Reviewed Publication

INDIANA UNIVERSITY

 

IMAGE: THIS RAW IMAGE FROM THE CURIOSITY ROVER SHOWS THE HEXAGON-SHAPED MUDCRACKS FILLED WITH SALT. view more 

CREDIT: NASA/JPL-CALTECH/MSSS, LANL.

That the planet Mars had habitable surface environments early in its existence has been firmly established by the scientific community.  These environments provided water, energy sources, elements like carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur, as well as critical catalytic transition metals associated with life as we know it. However, whether that potential stimulated further progression towards the independent evolution of life on Mars is unknown.

A team of scientists comprised of Juergen Schieber, a Professor in the Department of Earth and Atmospheric Sciences within the College of Arts and Sciences at Indiana University Bloomington, and colleagues on NASA’s Curiosity Rover mission, uncovered the first tangible evidence for sustained wet-dry cycling on early Mars. The latter condition is considered essential for prebiotic chemical evolution, a stepping-stone towards the emergence of life.

In a new paper, “Sustained wet-dry cycling on early Mars,” published in the scientific journal Nature, Schieber and his co-authors utilized data from the Curiosity Rover that currently explores Gale Crater to examine ancient pattern of mudcracks filled with salt (geometric patterns like pentagons or hexagons) observed in 3.6 billion year old mudstones.  As mud dries out, it shrinks and fractures into T-shaped junctions – like what Curiosity discovered previously at “Old Soaker,” a collection of mud cracks lower down on Mount Sharp. Those junctions are evidence that Old Soaker’s mud formed and dried out once, while the recurring exposures to water that created the new mud cracks caused the T-junctions to soften and become Y-shaped, eventually forming a hexagonal pattern.

Although Professor Schieber’s main research interest is the geology of shales and mudstones on Earth, his interest in the underlying fundamentals prompted him to postulate an abundance of mudstones on Mars, and that got him into a conversation with people that were planning the Mars Science Lab (MSL) Curiosity Rover mission at NASA’s Jet Propulsion Laboratory in Southern California. “Given my expertise about these rocks I was invited to join the MSL science team, and since landing in August 2012, 11 years ago almost to the day, our traverse has been dominated by mudstones,” said Professor Schieber.

Sustained wet-dry cycling on Mars—a consequence of a repeated desiccation, recharge, and flooding, creates cracks in the lake bed and within those cracks high salt concentrations develop that force the crystallization of minerals left after the lake’s evaporation, and cementation of sediment.  Ultimately this process was preserved as the polygonal (hexagon- or pentagon-shaped) patterns observed with the Rover. Due to desiccation, the residual water likely had high concentrations of dissolved salts and, potentially, of organic molecules that can serve as the building blocks of life.

“The theory is, that as these elements and organic molecules are forced closer and closer together with increasing salinity, they may start polymerizing and make longer chains, creating the conditions for spontaneous chemistry that may start the complex chemical evolution that could lead to living organisms,” said Schieber. “It is that mental image that got us excited when we observed these honeycomb-shaped, or polygonal, ridge patterns on the surface of mudstone beds. Here was evidence for wetting and drying that could drive interesting chemistry within the cracks.”

Knowing from earlier studies that likely residuals from the lake’s desiccation should be calcium and magnesium sulfate minerals, the team used the “Chemcam” instrument on the Curiosity Rover to probe the cemented ridges to confirm their chemical composition.

The sedimentary features of the mudstones that Schieber and his co-authors studied can be interpreted to have resulted from multiple wetting and drying cycles resulting in mineral precipitates—minerals left behind when water evaporates—stacked on top of each other over time.  If organic molecules were present in residual brines, this setting may have been conducive to the evolution of more complex organic molecules and pre-biotic chemistry, the study authors report.

Overlays highlight the geometric patterns.

CREDIT

NASA/JPL-CALTECH/MSSS, LANL

JOURNAL

Nature

DOI

10.1038/s41586-023-06220-3 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Sustained wet–dry cycling on early Mars

ARTICLE PUBLICATION DATE

9-Aug-2023