Category: Environment

{Pollinator insects accelerate plant evolution, but a plant changes in different ways depending on the pollinator. After only nine generations, the same plant is larger and more fragrant if pollinated by bumblebees rather than flies, as a study conducted by evolutionary biologists from the University of Zurich reveals.}

Not much plant sex happens without pollinator insects: Bees, flies or butterflies transfer the male pollen grains to the stigma of a plant’s female style, thereby ensuring its sexual reproduction. Researchers from the Department of Systematic and Evolutionary Botany at the University of Zurich now reveal that pollinator insects also have a surprisingly strong influence on plant evolution.

{{Plants pollinated by bumblebees become more fragrant}}

For their experiment, UZH professor Florian Schiestl and doctoral student Daniel Gervasi used field mustard — a kind of cabbage species and a close relative of oilseed rape. The researchers allowed one plant group to be pollinated solely by bumblebees for nine generations, another only by hoverflies and a third by hand. Afterwards they analyzed the plants, “which differed greatly,” as Florian Schiestl explains. The plants pollinated by bumblebees were larger and had more fragrant flowers with a greater UV color component, which bees and their relatives see. The plants pollinated by hoverflies, on the other hand, were smaller, their flowers were less fragrant and they self-pollinated considerably more. According to Schiestl, the mechanism of evolutionary change is fact that different pollinators differ in their preferences and thus preferentially cross-pollinate specific plant individuals, much like a plant breeder using individuals with favorable properties. The flies’ considerably lower pollination efficiency is the cause of the increase in self-pollination. The plants essentially help themselves if the pollinator transfers too little pollen.

{{Pollinator insects hasten plant evolution}}

The fact that the plants change so significantly already after nine generations came as a surprise to the researchers: “The traditional assumption is that evolution is a slow process,” explains Schiestl. The evolutionary biologist from UZH draws the following conclusion from his results: “A change in the composition of pollinator insects in natural habitats can trigger a rapid evolutionary transformation in plants.” This is particularly interesting as certain pollinator insects such as bees have been vastly decimated by the extensive use of pesticides and the depletion of the landscape in recent decades. According to Schiestl, it would thus be conceivable for plants to increasingly rely on flies as pollinators, which would result in the evolution of weaker flower fragrances and more self-pollination. In the longer term, this would reduce a plant population’s genetic variability and the plants would become more susceptible to disease.

Science Daily

{New research challenges the idea that changes in the Earth’s orbit triggered Sahara desertification.}

New research investigating the transition of the Sahara from a lush, green landscape 10,000 years ago to the arid conditions found today, suggests that humans may have played an active role in its desertification.

The desertification of the Sahara has long been a target for scientists trying to understand climate and ecological tipping points. A new paper published in Frontiers in Earth Science by archeologist Dr. David Wright, from Seoul National University, challenges the conclusions of most studies done to date that point to changes in the Earth’s orbit or natural changes in vegetation as the major driving forces.

“In East Asia there are long established theories of how Neolithic populations changed the landscape so profoundly that monsoons stopped penetrating so far inland,” explains Wright, also noting in his paper that evidence of human-driven ecological and climatic change has been documented in Europe, North America and New Zealand. Wright believed that similar scenarios could also apply to the Sahara.

To test his hypothesis, Wright reviewed archaeological evidence documenting the first appearances of pastoralism across the Saharan region, and compared this with records showing the spread of scrub vegetation, an indicator of an ecological shift towards desert-like conditions. The findings confirmed his thoughts; beginning approximately 8,000 years ago in the regions surrounding the Nile River, pastoral communities began to appear and spread westward, in each case at the same time as an increase in scrub vegetation.

Growing agricultural addiction had a severe effect on the region’s ecology. As more vegetation was removed by the introduction of livestock, it increased the albedo (the amount of sunlight that reflects off the earth’s surface) of the land, which in turn influenced atmospheric conditions sufficiently to reduce monsoon rainfall. The weakening monsoons caused further desertification and vegetation loss, promoting a feedback loop which eventually spread over the entirety of the modern Sahara.

There is much work still to do to fill in the gaps, but Wright believes that a wealth of information lies hidden beneath the surface: “There were lakes everywhere in the Sahara at this time, and they will have the records of the changing vegetation. We need to drill down into these former lake beds to get the vegetation records, look at the archaeology, and see what people were doing there. It is very difficult to model the effect of vegetation on climate systems. It is our job as archaeologists and ecologists to go out and get the data, to help to make more sophisticated models.”

Despite taking place several thousands of years ago, the implications of humans being responsible for environmental and climatic degradation are easy to see. With approximately 15% of the world’s population living in desert regions, Wright stresses the importance of his findings: “the implications for how we change ecological systems have a direct impact on whether humans will be able to survive indefinitely in arid environments.”

Source:Science Daily

{Scientists have identified a previously unknown virus that decreases the number of female offspring of the wasps it infects, according to a PLOS Pathogens study. The virus, discovered by Gongyin Ye’s group of Zhejiang University, infects one species of a specific group of wasps known as parasitoid wasps.}

Parasitoid wasps lay their eggs inside the bodies of the host insects. After the eggs hatch, the young wasps spend the first part of their life cycle feeding on the host insect until it dies. Many parasitoid wasps have symbiotic relationships with viruses that enable wasps to produce substances that weaken the host insect immune defense and help the wasps survive.

While studying a parasitoid wasp species known as Pteromalus puparum, Ye’s team discovered signs of a virus among products of the wasp’s transcriptome. They sequenced the viral genome and found that it belonged to a previously unknown species. The virus, dubbed PpNSRV-1 represents a novel genus of the taxonomic order Mononegavirales, making it the first virus of that genus to be found in parasitoid wasps.

After identifying PpNSRV-1, the researchers investigated its influence on infected wasps. They compared wasps infected by PpNSRV-1 with non-infected wasps and found that the virus lengthens the lifespan of the wasps. The scientists hypothesize that this could help the virus by giving wasps more time to transmit the virus to more hosts.

PpNSRV-1 also reduces the number of female offspring produced by the wasp. The scientists speculate that a reduced number of female offspring could also promote viral transmission. This is because both males and female wasps appear to be able to pass PpNSRV-1 to offspring, and since males can mate with multiple females, a higher ratio of males could spread the virus farther. It is first reported that the virus associated with parasitoid wasps has the key role in regulating wasp offspring sex ratio before which only bacterial symbionts such as Wolbachia are considered to be related to regulate its host wasp sex ratio.

Much more research is needed to better understand PpNSRV-1 and its full impact on wasps. For example, while the virus may extend wasp lifespan in the lab, it may not do so in nature. Better understanding of parasitoid wasps in general is useful since their insect-killing tendencies make some of them valuable for insect control in agriculture.

Source:Science Daily

{Mars may have been a wetter place than previously thought, according to research on simulated Martian meteorites conducted, in part, at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).}

In a study published today in the journal Nature Communications, researchers found evidence that a mineral found in Martian meteorites — which had been considered as proof of an ancient dry environment on Mars — may have originally been a hydrogen-containing mineral that could indicate a more water-rich history for the Red Planet.

Scientists at the University of Nevada, Las Vegas (UNLV), who led an international research team in the study, created a synthetic version of a hydrogen-containing mineral known as whitlockite.

After shock-compression experiments on whitlockite samples that simulated the conditions of ejecting meteorites from Mars, the researchers studied their microscopic makeup with X-ray experiments at Berkeley Lab’s Advanced Light Source (ALS) and at Argonne National Laboratory’s Advanced Photon Source (APS).

The X-ray experiments showed that whitlockite can become dehydrated from such shocks, forming merrillite, a mineral that is commonly found in Martian meteorites but does not occur naturally on Earth.

“This is important for deducing how much water could have been on Mars, and whether the water was from Mars itself rather than comets or meteorites,” said Martin Kunz, a staff scientist at Berkeley Lab’s ALS who participated in X-ray studies of the shocked whitlockite samples.

“If even a part of merrillite had been whitlockite before, it changes the water budget of Mars dramatically,” said Oliver Tschauner, a professor of research in the Department of Geoscience at UNLV who co-led the study with Christopher Adcock, an assistant research professor at UNLV.

And because whitlockite can be dissolved in water and contains phosphorus, an essential element for life on Earth — and merrillite appears to be common to many Martian meteorites — the study could also have implications for the possibility of life on Mars.

“The overarching question here is about water on Mars and its early history on Mars: Had there ever been an environment that enabled a generation of life on Mars?” Tschauner said.

The pressures and temperatures generated in the shock experiments, while comparable to those of a meteorite impact, lasted for only about 100 billionths of a second, or about one-tenth to one-hundredth as long as an actual meteorite impact.

The fact that experiments showed even partial conversion to merrillite in these lab-created conditions, a longer duration impact would likely have produced “almost full conversion” to merrillite, Tschauner said.

He added that this latest study appears to be one of the first of its kind to detail the shock effects on synthetic whitlockite, which is rare on Earth.

Researchers blasted the synthetic whitlockite samples with metal plates fired from a gas-pressurized gun at speeds of up to about half a mile per second, or about 1,678 miles per hour, and at pressures of up to about 363,000 times greater than the air pressure in a basketball.

“You need a very severe impact to accelerate material fast enough to escape the gravitational pull of Mars,” Tschauner said.

At Berkeley Lab’s ALS, researchers used an X-ray beam to study the microscopic structure of shocked whitlockite samples in a technique known as X-ray diffraction. The technique allowed researchers to differentiate between merrillite and whitlockite in the shocked samples.

Separate X-ray experiments carried out at Argonne Lab’s APS showed that up to 36 percent of whitlockite was transformed to merrillite at the site of the metal plate’s impact with the mineral, and that shock-generated heating rather than compression may play the biggest role in whitlockite’s transformation into merrillite.

There is also evidence that liquid water flows on Mars today, though there has not yet been scientific proof that life has ever existed on Mars. In 2013, planetary scientists reported that darkish streaks that appear on Martian slopes are likely related to periodic flows of water resulting from changing temperatures. They based their analysis on data from NASA’s Mars Reconnaissance Orbiter.

And in November 2016, NASA scientists reported that a large underground body of water ice in one region of Mars contains the equivalent of all of the water in Lake Superior, the largest of the Great Lakes. Rover explorations have also found evidence of the former abundance of water based on analysis of surface rocks.

“The only missing link now is to prove that (merrillite) had, in fact, really been Martian whitlockite before,” Tschauner said. “We have to go back to the real meteorites and see if there had been traces of water.”

Adcock and Tschauner are pursuing another round of studies using infrared light at the ALS to study actual Martian meteorite samples, and are also planning X-ray studies of these actual samples this year.

Many Martian meteorites found on Earth seem to come from a period of about 150 million to 586 million years ago, and most are likely from the same region of Mars. These meteorites are essentially excavated from a depth of about a kilometer below the surface by the initial impact that sent them out into space, so they aren’t representative of the more recent geology at the surface of Mars, Tschauner explained.

“Most of them are very similar in the rock composition as well as the minerals that are occurring, and have a similar impact age,” he said. Mars is likely to have formed about 4.6 billion years ago, about the same time as Earth and the rest of our solar system.

Even with more detailed studies of Martian meteorites coupled with thermal imaging of Mars taken from orbiters, and rock samples analyzed by rovers traversing the planet’s surface, the best evidence of Mars’ water history would be an actual Martian rock taken from the planet and transported back to Earth, intact, for detailed studies, researchers noted.

“It’s really important to get a rock that hasn’t been ‘kicked’” like the Martian meteorites have, said Kunz, in order to learn more about the planet’s water history.

Source:Science Daily

{Trees domesticated by pre-Columbian peoples remain more common in forests near ancient settlements.}

We often think of the Amazon rainforest as a vast expanse of nature untouched by humans. But a new study in Science suggests that’s not true — in fact, today’s rainforest is shaped by trees that were cultivated by indigenous peoples thousands of years ago.

“Some of the tree species that are abundant in Amazonian forests today, like cacao, açaí, and Brazil nut, are probably common because they were planted by people who lived there long before the arrival of European colonists,” says Nigel Pitman, the Mellon Senior Conservation Ecologist at Chicago’s Field Museum and a co-author of the study.

The team made the discovery by overlaying data from more than 1,000 forest surveys on a map of more than 3,000 archaeological sites across the Amazon. By comparing forest composition at varying distances from archaeological sites, the analysis generated the first Amazon-wide picture of how pre-Columbian peoples influenced Amazonian biodiversity. The study focused on 85 tree species known to have been domesticated by Amazonian peoples for food, shelter, or other uses over the last several thousand years. The researchers found that throughout the Amazon basin, these species were five times more likely to be common in mature upland forests than non-domesticated species. In some parts of the basin, domesticated species were found to be both more common and more diverse in forests closer to archaeological sites.

“That’s even the case for some really remote, mature forests that we’d typically assumed to be pristine and undisturbed,” says Pitman.

The finding promises to heat up a long-simmering debate among scientists about how thousands of years of human settlement in the Amazon basin have influenced modern-day patterns of Amazonian biodiversity. The immense size of Amazonian forests has historically hampered archaeological research and given the impression of an untouched landscape, but a large number of new archaeological sites have been discovered in recent years.

The team, made up by hundreds of ecologists and social scientists worldwide, was led by Carolina Levis, a PhD student at Brazil’s National Institute for Amazonian Research and Wagenigen University and Research in the Netherlands. “For many years, ecological studies ignored the influence of pre-Columbian peoples on the forests we see today. We found that a quarter of these domesticated tree species are widely distributed in the basin and dominate large expanses of forest. These species are vital for the livelihood and economy of Amazonian peoples and indicate that the Amazonian flora is in part a surviving heritage of its former inhabitants,” says Levis.

The study also pinpointed regions of the Amazon that today concentrate especially high diversities and large populations of domesticated species. Southwestern Amazonia, where large stands of Brazil nut trees remain a foundation of local residents’ livelihoods, is one such example. Other regions showed fewer domesticated species, or a weaker relationship between domesticated species and archeological sites, highlighting the need for more research on the history of Amazonian settlement. The degree to which the recent history of Amazonian settlement has affected the distribution and abundance of domesticated species in the Amazon also remains to be studied.

While the small number of domesticated species used in the study was sufficient to reveal a strong human signal in modern forests, the authors point out that the signal may be even stronger than they documented, since hundreds of other Amazonian tree species were used by pre-Colombian peoples and also deserve study. Untangling the complex interplay of historical, environmental, and ecological factors structuring the 16,000-species Amazonian tree flora remains a focus of the team’s work.

“The questions are pressing,” says Pitman, “since both types of pre-Columbian heritage — archeological sites and the forests that surround them — are at risk from road-building, mining, and other threats to the Amazon.”

Source:Science Daily

{Humans have dramatically increased the spatial and seasonal extent of wildfires across the U.S. in recent decades and ignited more than 840,000 blazes in the spring, fall and winter seasons over a 21-year period, according to new research.}

After analyzing two decades’ worth of U.S. government agency wildfire records spanning 1992-2012, the researchers found that human-ignited wildfires accounted for 84 percent of all wildfires, tripling the length of the average fire season and accounting for nearly half of the total acreage burned.

The findings were published in the journal Proceedings of the National Academy of Sciences.

“There cannot be a fire without a spark,” said Jennifer Balch, Director of CU Boulder’s Earth Lab and an assistant professor in the Department of Geography and lead author of the new study. “Our results highlight the importance of considering where the ignitions that start wildfires come from, instead of focusing only on the fuel that carries fire or the weather that helps it spread. Thanks to people, the wildfire season is almost year-round.”

The U.S. has experienced some of its largest wildfires on record over the past decade, especially in the western half of the country. The duration and intensity of future wildfire seasons is a point of national concern given the potentially severe impact on agriculture, ecosystems, recreation and other economic sectors, as well as the high cost of extinguishing blazes.

The annual cost of fighting wildfires in the U.S. has exceeded $2 billion in recent years.

The CU Boulder researchers used the U.S. Forest Service Fire Program Analysis-Fire Occurrence Database to study records of all wildfires that required a response from a state or federal agency between 1992 and 2012, omitting intentionally set prescribed burns and managed agricultural fires. Human-ignited wildfires accounted for 84 percent of 1.5 million total wildfires studied, with lightning-ignited fires accounting for the rest.

In Colorado, 30 percent of wildfires from 1992-2012 were started by people, burning over 1.2 million acres. The fire season length for human-started fires was 50 days longer than the lightning-started fire season (93 days compared to 43 days), a twofold increase.

“These findings do not discount the ongoing role of climate change, but instead suggest we should be most concerned about where it overlaps with human impact,” said Balch. “Climate change is making our fields, forests and grasslands drier and hotter for longer periods, creating a greater window of opportunity for human-related ignitions to start wildfires.”

While lightning-driven fires tend to be heavily concentrated in the summer months, human-ignited fires were found to be more evenly distributed across all seasons. Overall, humans added an average of 40,000 wildfires during the spring, fall and winter seasons annually — over 35 times the number of lightning-started fires in those seasons.

“We saw significant increases in the numbers of large, human-started fires over time, especially in the spring,” said Bethany Bradley, an associate professor at University of Massachusetts Amherst and co-lead author of the research. “I think that’s interesting, and scary, because it suggests that as spring seasons get warmer and earlier due to climate change, human ignitions are putting us at increasing risk of some of the largest, most damaging wildfires.”

“Not all fire is bad, but humans are intentionally and unintentionally adding ignitions to the landscape in areas and seasons when natural ignitions are sparse,” said John Abatzoglou, an associate professor of geography at the University of Idaho and a co-author of the paper. “We can’t easily control how dry fuels get, or lightning, but we do have some control over human started ignitions.”

The most common day for human-started fire by far, however, was July 4, with 7,762 total wildfires started on that day over the course of the 21-year period.

The new findings have wide-ranging implications for fire management policy and suggest that human behavior can have dramatic impact on wildfire totals, for good or for ill.

“The hopeful news here is that we could, in theory, reduce human-started wildfires in the medium term,” said Balch. “But at the same time, we also need to focus on living more sustainably with fire by shifting the human contribution to ignitions to more controlled, well-managed burns.”

Source:Science Daily

{In November 2015, the research group presented results showing that they had caused roses to absorb a conducting polymer solution. Conducting hydrogel formed in the rose’s stem in the form of wires. With an electrode at each end and a gate in the middle, a fully functional transistor was created. The results were recently presented in Science Advances.}

One member of the group, Assistant Professor Roger Gabrielsson, has now developed a material specially designed for this application. The material polymerizes inside the rose without any external trigger. The innate fluid that flows inside the rose contributes to create long, conducting threads, not only in the stem but also throughout the plant, out into the leaves and petals.

“We have been able to charge the rose repeatedly, for hundreds of times without any loss on the performance of the device. The levels of energy storage we have achieved are of the same order of magnitude as those in supercapacitors. The plant can, without any form of optimization of the system, potentially power our ion pump, for example, and various types of sensors,” says Eleni Stavrinidou, Assistant Professor at the Laboratory of Organic Electronics.

The results are now to be published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

“This research is in a very early stage, and what the future will bring is an open question,” says Eleni Stavrinidou.

Some examples are autonomous energy systems, the possibility of harvesting energy from plants to power sensors and various types of switches, and the possibility of creating fuel cells inside plants.

“A few years ago, we demonstrated that it is possible to create electronic plants, ‘power plants’, but we have now shown that the research has practical applications. We have not only shown that energy storage is possible, but also that we can deliver systems with excellent performance,” says Professor Magnus Berggren, head of the Laboratory of Organic Electronics, Linköping University, Campus Norrköping.

The research into electronic plants has been funded by unrestricted research grants from the Knut and Alice Wallenberg Foundation. The foundation appointed Professor Magnus Berggren a Wallenberg Scholar in 2012.

Source:Science Daily

{New Mars research shows evidence of a complex mantle beneath the Elysium volcanic province.}

Mars’ mantle may be more complicated than previously thought. In a new study published in the Nature-affiliated journal Scientific Reports, researchers at LSU document geochemical changes over time in the lava flows of Elysium, a major martian volcanic province.

LSU Geology and Geophysics graduate researcher David Susko led the study with colleagues at LSU including his advisor Suniti Karunatillake, the University of Rahuna in Sri Lanka, the SETI Institute, Georgia Institute of Technology, NASA Ames, and the Institut de Recherche en Astrophysique et Planétologie in France.

They found that the unusual chemistry of lava flows around Elysium is consistent with primary magmatic processes, such as a heterogeneous mantle beneath Mars’ surface or the weight of the overlying volcanic mountain causing different layers of the mantle to melt at different temperatures as they rise to the surface over time.

Elysium is a giant volcanic complex on Mars, the second largest behind Olympic Mons. For scale, it rises to twice the height of Earth’s Mount Everest, or approximately 16 kilometers. Geologically, however, Elysium is more like Earth’s Tibesti Mountains in Chad, the Emi Koussi in particular, than Everest. This comparison is based on images of the region from the Mars Orbiter Camera, or MOC, aboard the Mars Global Surveyor, or MGS, Mission.

Elysium is also unique among martian volcanoes. It’s isolated in the northern lowlands of the planet, whereas most other volcanic complexes on Mars cluster in the ancient southern highlands. Elysium also has patches of lava flows that are remarkably young for a planet often considered geologically silent.

“Most of the volcanic features we look at on Mars are in the range of 3-4 billion years old,” Susko said. “There are some patches of lava flows on Elysium that we estimate to be 3-4 million years old, so three orders of magnitude younger. In geologic timescales, 3 million years ago is like yesterday.”

In fact, Elysium’s volcanoes hypothetically could still erupt, Susko said, although further research is needed to confirm this. “At least, we can’t yet rule out active volcanoes on Mars,” Susko said. “Which is very exciting.”

Susko’s work in particular reveals that the composition of volcanoes on Mars may evolve over their eruptive history. In earlier research led by Karunatillake, assistant professor in LSU’s Department of Geology and Geophysics, researchers in LSU’s Planetary Science Lab, or PSL, found that particular regions of Elysium and the surrounding shallow subsurface of Mars are geochemically anomalous, strange even relative to other volcanic regions on Mars. They are depleted in the radioactive elements thorium and potassium. Elysium is one of only two igneous provinces on Mars where researchers have found such low levels of these elements so far.

“Because thorium and potassium are radioactive, they are some of the most reliable geochemical signatures that we have on Mars,” Susko said. “They act like beacons emitting their own gamma photons. These elements also often couple in volcanic settings on Earth.”

In their new paper, Susko and colleagues started to piece together the geologic history of Elysium, an expansive volcanic region on Mars characterized by strange chemistry. They sought to uncover why some of Elysium’s lava flows are so geochemically unusual, or why they have such low levels of thorium and potassium. Is it because, as other researchers have suspected, glaciers located in this region long ago altered the surface chemistry through aqueous processes? Or is it because these lava flows arose from different parts of Mars’ mantle than other volcanic eruptions on Mars?

Perhaps the mantle has changed over time, meaning that more recent volcanic eruption flows differ chemically from older ones. If so, Susko could use Elysium’s geochemical properties to study how Mars’ bulk mantle has evolved over geologic time, with important insights for future missions to Mars. Understanding the evolutionary history of Mars’ mantle could help researchers gain a better understanding of what kinds of valuable ores and other materials could be found in the crust, as well as whether volcanic hazards could unexpectedly threaten human missions to Mars in the near future. Mars’ mantle likely has a very different history than Earth’s mantle because the plate tectonics on Earth are absent on Mars as far as researchers know. The history of the bulk interior of the red planet also remains a mystery.

Susko and colleagues at LSU analyzed geochemical and surface morphology data from Elysium using instruments on board NASA’s Mars Odyssey Orbiter (2001) and Mars Reconnaissance Orbiter (2006). They had to account for the dust that blankets Mars’ surface in the aftermath of strong dust storms, to make sure that the shallow subsurface chemistry actually reflected Elysium’s igneous material and not the overlying dust.

Through crater counting, the researchers found differences in age between the northwest and the southeast regions of Elysium — about 850 million years of difference. They also found that the younger southeast regions are geochemically different from the older regions, and that these differences in fact relate to igneous processes, not secondary processes like the interaction of water or ice with the surface of Elysium in the past.

“We determined that while there might have been water in this area in the past, the geochemical properties in the top meter throughout this volcanic province are indicative of igneous processes,” Susko said. “We think levels of thorium and potassium here were depleted over time because of volcanic eruptions over billions of years. The radioactive elements were the first to go in the early eruptions. We are seeing changes in the mantle chemistry over time.”

“Long-lived volcanic systems with changing magma compositions are common on Earth, but an emerging story on Mars,” said James Wray, study co-author and associate professor in the School of Earth and Atmospheric Sciences at Georgia Tech.

Wray led a 2013 study that showed evidence for magma evolution at a different martian volcano, Syrtis Major, in the form of unusual minerals. But such minerals could be originating at the surface of Mars, and are visible only on rare dust-free volcanoes.

“At Elysium we are truly seeing the bulk chemistry change over time, using a technique that could potentially unlock the magmatic history of many more regions across Mars,” he said.

Susko speculates that the very weight of Elysium’s lava flows, which make up a volcanic province six times higher and almost four times wider than its morphological sister on Earth, Emi Koussi, has caused different depths of Mars’ mantle to melt at different temperatures. In different regions of Elysium, lava flows may have come from different parts of the mantle. Seeing chemical differences in different regions of Elysium, Susko and colleagues concluded that Mars’ mantle might be heterogeneous, with different compositions in different areas, or that it may be stratified beneath Elysium.

Overall, Susko’s findings indicate that Mars is a much more geologically complex body than originally thought, perhaps due to various loading effects on the mantle caused by the weight of giant volcanoes.

“It’s more Earth-like than moon-like,” Susko said. “The moon is cut and dry. It often lacks the secondary minerals that occur on Earth due to weathering and igneous-water interactions. For decades, that’s also how we envisioned Mars, as a lifeless rock, full of craters with a number of long inactive volcanoes. We had a very simple view of the red planet. But the more we look at Mars, the less moon-like it becomes. We’re discovering more variety in rock types and geochemical compositions, as seen across the Curiosity Rover’s traverse in Gale Crater, and more potential for viable resource utilization and capacity to sustain a human population on Mars. It’s much easier to survive on a complex planetary body bearing the mineral products of complex geology than on a simpler body like the moon or asteroids.”

Susko plans to continue clarifying the geologic processes that cause the strange chemistry found around Elysium. In the future, he will study these chemical anomalies through computational simulations, to determine if recreating the pressures in Mars’ mantle caused by the weight of giant volcanoes could affect mantle melting to yield the type of chemistry observed within Elysium.

Source:Science Daily