Tuesday, November 03, 2020

Lizard skull fossil is new and 'perplexing' extinct species

ANOTHER AMAZING FIND IN THE MUSEUM STORAGE ROOM

UNIVERSITY OF TEXAS AT AUSTIN

IMAGE: A CT IMAGE OF THE KOPIDOSAURUS PERPLEXUS SKULL IN LEFT LATERAL VIEW. view more
CREDIT: SIMON SCARPETTA

In 2017, while browsing the fossil collections of Yale's Peabody Museum of Natural History, University of Texas at Austin graduate student Simon Scarpetta came across a small lizard skull, just under an inch long.

The skull was beautifully preserved, with a mouth full of sharp teeth - including some with a distinctive curve.

Much to Scarpetta's surprise, no one had studied it. Since being discovered in 1971 on a museum fossil hunting trip to Wyoming, the 52 million-year-old skull had sat in the specimen drawer.

"Lizards are small and prone to breaking apart, so you mostly get these individual, isolated fragmented bones," said Scarpetta, who is studying paleontology at the UT Jackson School of Geosciences. "Anytime you find a skull, especially when you're trying to figure out how things are related to each other, it's always an exciting find."

Scarpetta decided to bring the skull back to the Jackson School for a closer look. And on September 2020, the journal Scientific Reports published a study authored by Scarpetta describing the lizard as a new species, which he named Kopidosaurus perplexus.

The first part of the name references the lizard's distinct teeth; a "kopis" is a curved blade used in ancient Greece. But the second part is a nod to the "perplexing" matter of just where the extinct lizard should be placed on the tree of life. According to an analysis conducted by Scarpetta, the evidence points to a number of plausible spots.

The spots can be divided into two groups of lizards, representing two general hypotheses of where the new species belongs. But adding to the uncertainty is that how those two groups relate to one another can shift depending on the particular evolutionary tree that's examined. Scarpetta examined three of these trees - each one built by other researchers studying the evolutionary connections of different reptile groups using DNA - and suggests that there could be a forest of possibilities where the ancient lizard could fit.

The case of where exactly to put the perplexing lizard highlights an important lesson for paleontologists: just because a specimen fits in one place doesn't mean that it won't fit equally well into another.

"The hypothesis that you have about how different lizards are related to each other is going to influence what you think this one is," Scarpetta said.

Paleontologists use anatomical details present in bones to discern the evolutionary relationships of long-dead animals. To get a close look at the lizard skull, Scarpetta created a digital scan of it in the Jackson School's High-Resolution X-Ray CT Lab. However, while certain details helped identify the lizard as a new species, other details overlapped with features from a number of different evolutionary groups.

All of these groups belonged to a larger category known as Iguania, which includes a number of diverse species, including chameleons, anoles and iguanas. To get a better idea of where the new species might fit into the larger Iguania tree, Scarpetta compared the skull data to evolutionary trees for Iguania that were compiled by other researchers based on DNA evidence from living reptiles.

On each tree, the fossil fit equally well into two general spots. What's more, the lizard groupings in each spot varied from tree to tree. If Scarpetta had just stopped at one spot or one tree, he would have missed alternative explanations that appear just as plausible as the others.

Scarpetta said that Kopidosaurus perplexus is far from the only fossil that could easily fit onto multiple branches on the tree of life. Paleontologist Joshua Lively, a curator at the Utah State University Eastern Prehistoric Museum, agrees and said that this study epitomizes why embracing uncertainty can lead to better, more accurate science.

"Something that I think the broader scientific community should pull from this is that you have to be realistic about your data and acknowledge what we can actually pull from our results and conclude and where there are still uncertainties," Lively said. "Simon's approach is the high bar, taking the high road. It's acknowledging what we don't know and really embracing that."

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The research was funded by the Jackson School of Geosciences and the Geological Society of America.

Genomic data 'catches corals in the act' of speciation and adaptation

UNIVERSITY OF HAWAII AT MANOA

Research News

IMAGE: A) PORITES LOBATA (YELLOW MASSIVE MORPHOLOGY) SHOWN NEXT TO PORITES COMPRESSA (BLUE-GREY BRANCHING MORPHOLOGY) SIDE BY SIDE IN THE SAME HABITAT; (B) EXAMPLE OF VARIATION IN BLEACHING SUSCEPTIBILITY OF P. COMPRESSA... view more
CREDIT: FORSMAN, ET AL. (2020)

A new study led by the University of Hawai'i at Mānoa's Hawai'i Institute of Marine Biology (HIMB) revealed that diversity in Hawaiian corals is likely driven by co-evolution between the coral host, the algal symbiont, and the microbial community.

As coral reef ecosystems have rapidly collapsed around the globe over the past few decades, there is widespread concern that corals might not be able to adapt to changing climate conditions, and much of the biodiversity in these ecosystems could be lost before it is studied and understood. Coral reefs are among the most highly biodiverse ecosystems on earth, yet it is not clear what drives speciation and diversification in the ocean, where there are few physical barriers that could separate populations.

The team of researchers used massive amounts of metagenomic sequencing data to try to understand what may be some of the major drivers of adaptation and variation in corals.

"Corals have incredible variation with such a wide range of shapes, sizes, and colors that it's really hard for even the best trained experts to be able to sort out different species," said Zac Forsman, lead author of the study and HIMB assistant researcher. "On top of that, some corals lose their algal symbionts, turning stark white or 'bleached' and die during marine heatwaves, while a similar looking coral right next to it seems fine. We wanted to try to better understand what might be driving some of this incredible variation that you see on a typical coral reef."

Forsman and colleagues examined genetic relationships within the coral genus Porites, which forms the foundation and builds many coral reefs around the world. They were able to identify genes from the coral, algal symbionts, and bacteria that were most strongly associated with coral bleaching and other factors such as the shape (morphology) of the coral colony. They found relatively few genes associated with bleaching, but many associated with distance from shore, and colony morphologies that dominate different habitats.

"We sought out to better understand coral bleaching and place it in the context of other sources of variation in a coral species complex. Unexpectedly, we found evidence that these corals have adapted and diverged very recently over depth and distance from shore. The algal symbionts and microbes were also in the process of diverging, implying that co-evolution is involved. It's like we caught them in the act of adaptation and speciation."

"These corals have more complex patterns of variation related to habitat than we could have imagined and learning about how corals have diversified over various habitats can teach us about how they might adapt in the future," he explained. "Since variation is the raw material for adaptation, there is hope for the capacity of these corals to adapt to future conditions, but only if we can slow down the pace of loss."

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First Australian night bees recorded foraging in darkness

A new study has identified two Australian beesthat have adapted their vision at night for the first time

FLINDERS UNIVERSITY

Research News

Australian bees are known for pollinating plants on beautiful sunny days, but a new study has identified two species that have adapted their vision for night-time conditions for the first time.

The study by a team of ecology researchers has observed night time foraging behaviour by a nomiine (Reepenia bituberculata) and masked (Meroglossa gemmata) bee species, with both developing enlarged compound and simple eyes which allow more light to be gathered when compared to their daytime kin.

Published in the Journal of Hymenoptera Research, the researchers explain that this improved low-light ability could potentially also exist in other Australian species secretly active at night, with their image processing ability best observed through high-resolution close-up images.

Lead author PhD Candidate James Dorey, in the College of Science & Engineering at Flinders University, says the two Australian bee species active at night and during twilight hours are mostly found in Australia's tropical north, but there could potentially more in arid, subtropical and maybe even temperate conditions across the continent.

"We have confirmed the existence of at least two crepuscular bee species in Australia and there are likely to be many more that can forage both during the day and into the early morning or evening under low light conditions. It's true that bees aren't generally known to be very capable when it comes to using their eyes at night, but it turns out that low-light foraging is more common than currently thought," says Mr Dorey.

"Before this study, the only way to show that a bee had adapted to low-light was by using difficult-to-obtain behavioural observations, but we have found that you should be able to figure this out by using high-quality images of a specific bee."

Mr Dorey says bees that forage during dim-light conditions aren't studied enough with no previously reliable published records for any Australian species.

"Our study provides a framework to help identify low-light-adapted bees and the data that is needed to determine the behavioural traits of other species. This is important as we need to increase efforts to collect bee species outside of normal hours and publish new observations to better understand the role that they play in maintaining ecosystems."

The researchers outline why more needs to be understood about the behaviour of bee species to help protect them from the potential impacts of climate change.

"Global weather patterns are changing and temperatures in many parts of Australia are rising along with the risk of prolonged droughts and fires. So, we have to improve our understanding about insects pollinating at night or in milder parts of the day to avoid potential extinction risks or to mitigate loss of pollination services."

"This also means we have to highlight the species that operate in a narrow window of time and could be sensitive to climatic changes, so conservation becomes an important concern. Because quite frankly, we have ignored these species up until now."

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The new paper, Morphometric comparisons and novel observations of diurnal and low-light foraging bees (2020) by James B Dorey (Flinders University), Erinn P.Fagan Jeffries (University of Adelaide), Mark I. Stevens (South Australian Musuem, UniSA), Michael P. Schwarz (Flinders University) has been published in The Journal of Hymenoptera.

IMAGE: BAISHIYA KARST CAVE view more
CREDIT: HAN YUANYUAN

HOME OF KOOT HOOMI AND THE SECRET MASTERS

Denisovan DNA found in sediments of Baishiya Karst Cave on Tibetan Plateau

CHINESE ACADEMY OF SCIENCES HEADQUARTERS

Research NewsOne year after the publication of research on the Xiahe mandible, the first Denisovan fossil found outside of Denisova Cave, the same research team has now reported their findings of Denisovan DNA from sediments of the Baishiya Karst Cave (BKC) on the Tibetan Plateau where the Xiahe mandible was found. The study was published in Science on Oct. 29.

The research team was led by Prof. CHEN Fahu from the Institute of Tibetan Plateau Research (ITP) of the Chinese Academy of Sciences (CAS), Prof. ZHANG Dongju from Lanzhou University, Prof. FU Qiaomei from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of CAS, Prof. Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology, and Prof. LI Bo from University of Wollongong.

Using cutting-edge paleogenetic technology, the researchers successfully extracted Denisovan mtDNA from Late Pleistocene sediment samples collected during the excavation of BKC. Their results show that this Denisovan group is closely related to the late Denisovans from Denisova Cave, indicating Denisovans occupied the Tibetan Plateau for a rather long time and had probably adapted to the high-altitude environment.

Denisovans were first discovered and identified in 2010 by a research team led by Prof. Svante Pääbo. Almost a decade later, the Xiahe mandible was found on the Tibetan Plateau. As the first Denisovan fossil found outside of Denisova Cave, it confirmed that Denisovans had occupied the roof of the world in the late Middle Pleistocene and were widespread. Although the Xiahe mandible shed great new light on Denisovan studies, without DNA and secure stratigraphic and archaeological context, the information it revealed about Denisovans was still considerably restricted.

In 2010, a research team from Lanzhou University led by Prof. CHEN Fahu, current director of ITP, began to work in BKC and the Ganjia basin where it is located. Since then, thousands of pieces of stone artifacts and animal bones have been found. Subsequent analysis indicated that the stone artifacts were mainly produced using simple core-flake technology. Among animal species represented, gazelles and foxes dominated in the upper layers, but rhinoceros, wild bos and hyena dominated in the lower layers. Some of the bones had been burnt or have cut-marks, indicating that humans occupied the cave for a rather long time.

To determine when people occupied the cave, researchers used radiocarbon dating of bone fragments recovered from the upper layers and optical dating of sediments collected from all layers in the excavated profile. They measured 14 bone fragments and about 30,000 individual grains of feldspar and quartz minerals from 12 sediment samples to construct a robust chronological framework for the site. Dating results suggest that the deepest excavated deposits contain stone artifacts buried over ~190 ka (thousand years). Sediments and stone artifacts accumulated over time until at least ~45 ka or even later.

To determine who occupied the cave, researchers used sedimentary DNA technology to analyze 35 sediment samples specially collected during the excavation for DNA analysis. They captured 242 mammalian and human mtDNA samples, thus enriching the record of DNA related to ancient hominins. Interestingly, they detected ancient human fragments that matched mtDNA associated with Denisovans in four different sediment layers deposited ~100 ka and ~60 ka.

More interestingly, they found that the hominin mtDNA from 60 ka share the closest genetic relationship to Denisova 3 and 4 - i.e., specimens sampled from Denisova Cave in Altai, Russia. In contrast, mtDNA dating to ~100 ka shows a separation from the lineage leading to Denisova 3 and 4.

Using sedimentary DNA from BKC, researchers found the first genetic evidence that Denisovans lived outside of Denisova Cave. This new study supports the idea that Denisovans had a wide geographic distribution not limited to Siberia, and they may have adapted to life at high altitudes and contributed such adaptation to modern humans on the Tibetan Plateau.

However, there are still many questions left. For example, what's the latest age of Denisovans in BKC? Due to the reworked nature of the top three layers, it is difficult to directly associate the mtDNA with their depositional ages, which are as late as 20-30 ka BP. Therefore, it is uncertain whether these late Denisovans had encountered modern humans or not. In addition, just based on mtDNA, we still don't know the exact relationship between the BKC Denisovans, those from Denisova Cave in Siberia and modern Tibetans. Future nuclear DNA from this site may provide a tool to further explore thes

Trump Closes Campaign With Bold Anti-Democracy,

Pro-Political Violence Message

By Eric Levitz @EricLevitz

VISION 2020 NOV. 2, 2020

Block the vote. Photo: BRENDAN SMIALOWSKI/AFP via Getty Images

Donald Trump is trailing Joe Biden by 8.5 points nationally — the biggest polling deficit that any incumbent president has ever faced this late in a campaign. One major cause of Trump’s woes is his collapsing standing with self-described “moderate” voters. In 2016, Hillary Clinton won this group by 12 points; some recent polls have Biden winning it by roughly four times that margin.

But the president has a plan for expanding his coalition: He will reassure moderate skeptics by putting greater emphasis on his indifference to public health, contempt for democracy, and support for political violence.

Or at least, this is what Trump’s messaging might lead one to think. Over the past 24 hours, the president has vowed to fire Dr. Anthony Fauci, praised a caravan of Trump supporters that surrounded a Biden campaign bus in Texas and nearly ran it off the road, and argued that voters whose ballots aren’t counted on Election Night deserve to be disenfranchised.

Fauci, the government’s top infectious-disease expert, boasts a 64 percent job-approval rating, according to a recent Morning Consult survey. By contrast, approval of Trump’s handling of the coronavirus sits at just 39 percent.

And yet, at a rally in South Florida last night, when Trump’s die-hard supporters broke into a “Fire Fauci” chant, the president replied, “Don’t tell anybody, but let me wait until a little bit after the election.” This statement implies both that Trump intends to fire a widely trusted public-health official in the middle of a pandemic and that the only reason he hasn’t done so yet is that he does not want pro-Fauci voters to know his true intentions before they cast their ballots.

Although there is little polling on the subject, it seems safe to say that most Americans believe it is wrong for politicians to try to win elections by (1) declaring victory before all votes are counted, and then (2) asking partisan judges to throw out the remaining ballots. Nevertheless, Trump told reporters Monday, “I think it’s terrible when we can’t know the results of an election [on] the night of the election, in a modern-day age of computer,” going on to say that his campaign would “go in the night of [the election], as soon as that election is over” and attempt to halt the counting of absentee mail ballots.

In interviews with the New York Times, Trump advisers made his campaign’s intentions even more explicit:

Trump advisers said their best hope was if the president wins Ohio and Florida is too close to call early in the night, depriving Mr. Biden a swift victory and giving Mr. Trump the room to undermine the validity of uncounted mail-in ballots in the days after.

The president’s confidantes told the same story (with a bit more elaboration) to Axios:

Behind the scenes: Trump has privately talked through this scenario in some detail in the last few weeks, describing plans to walk up to a podium on election night and declare he has won.

For this to happen, his allies expect he would need to either win or have commanding leads in Ohio, Florida, North Carolina, Texas, Iowa, Arizona and Georgia.

Why it matters: Trump’s team is preparing to falsely claim that mail-in ballots counted after Nov. 3 — a legitimate count expected to favor Democrats — are evidence of election fraud.

Trump’s plan to exploit a partisan discrepancy in voting methods (with Democrats being more likely to cast mail-in ballots that are counted last in some key swing states) has long been clear: Over and over, the president has insinuated that he will declare himself the winner on Election Night if he is leading in partial returns — and then fight in court to halt the counting of further ballots. What is new, however, is the president and his advisers openly copping to this strategy. Further, in his remarks Monday, Trump didn’t just baselessly assert that mail ballots were rife with fraud; he also made the less factually problematic — but more openly anti-democratic — argument that last-minute mail ballots shouldn’t be counted because procrastinators don’t deserve to have their voices heard, saying, “If people wanted to get their ballots in, they should have gotten their ballots in long before that.”

Finally, on Friday, a bevy of trucks bearing Trump flags surrounded a Biden-Harris campaign bus in Texas Friday, with one vehicle pulling in front of the bus and then stopping in the middle of the highway, apparently trying to force the bus to halt, or pull off to the side of the road. This led the Biden campaign to cancel two events out of fear of political violence. The FBI has opened an investigation into the incident.

According to a new USA Today–Suffolk University Poll, three-fourths of Americans are worried about violence on Election Day. In surveys of which candidate the public trusts to better handle public safety, Biden has consistently held the advantage, with many voters apparently buying the Democratic nominee’s argument that Trump fans the flames of division and unrest.

And yet, on Sunday night, Trump said of those who nearly forced a Democratic campaign bus off the road in Texas, “In my opinion, these patriots did nothing wrong. Instead, the FBI & Justice should be investigating the terrorists, anarchists, and agitators of ANTIFA, who run around burning down our Democrat run cities and hurting our people!”

This is not the message you broadcast if you are trying to expand your minority coalition. No sane political strategist would advise a candidate to close by emphasizing his opposition to democracy, support for political violence targeting his rivals, and contempt for popular public-health officials. The fact that Trump’s advisers have told reporters that they intend to lie to the American public on Election Night — and then block the counting of votes thereafter — is even more puzzling. Perhaps they are trying to undermine the plan by discussing it on record; or perhaps they simply have no more impulse control than the president, and just felt like gabbing. Either way, to the extent that there is any strategy behind Trump’s statements, it is a strategy for retaining power through political violence and judicial malfeasance, not one for winning a free and fair election.

THE CHEAPEST COMPUTER IS A KEYBOARD

Raspberry Pi 400 is out: $70 (USD) for a complete PC with a faster Pi 4 in a keyboard

The Raspberry Pi 400 comes with 4GB RAM, a faster Raspberry Pi 4 and a built-in heatsink to keep it cool.

By Liam Tung | November 2, 2020 -- 10:43 GMT (02:43 PST) | Topic: Hardware

Lockdown surge for Raspberry Pi sales

The makers of the Raspberry Pi 4 have today unveiled the Raspberry Pi 400, a compact keyboard with an integrated 4GB RAM Raspberry 4.

The new design takes most of the work out of setting up a Raspberry Pi 4 single-board computer (SBC) as a computer, which usually requires hooking it up to a keyboard, monitor and mouse.

With the Raspberry Pi 400, just a few cables, a monitor and mouse are needed to have a basic desktop computer to start programming, surf the web, and enjoy 4K media streaming.

Just in time for the holiday season, the Raspberry Pi 400 keyboard with a computer costs $70. Alternatively, $100 buys you the Raspberry Pi 400 Personal Computer Kit, which includes the Raspberry Pi 400, a USB mouse and USB-C power supply, an SD card with Raspberry Pi OS pre-installed, a micro HDMI cable for the display, and a Raspberry Pi Beginner's Guide.

The Raspberry Pi 4GB RAM version costs $55 by itself, and the Raspberry Pi 400 lowers the technical barrier for those who want to begin exploring programming on the low-cost computer and may inspire them to look at bigger projects using the Raspberry Pi SBC.

The Raspberry Pi 400 takes its design cue from the home computers of the 1980s that had their motherboard built into the keyboard, such as the BBC Micro, ZX Spectrum and Commodore Amiga.

Since the Raspberry Pi 400 is based on the Raspberry Pi 4, most of the computer features are the same. However, the Raspberry Pi 400's Broadcom BCM2711 quad-core Cortex-A72 (Arm v8) 64-bit SoC runs at 1.8GHz. As noted by CNX-Software, the Raspberry Pi 4's SoC runs at 1.5GHz.

Other key differences are that the Raspberry Pi 400 only offers HDMI for audio output where as the Pi 4 SBC also has a 3.5mm audio and video jack. There's also one fewer USB 2.0 port on the Raspberry Pi 400.

The Raspberry Pi 400 does feature a horizontal 40-pin GPIO header on the rear of the keyboard, so it's possible to add physical HAT extensions, such as a camera. There's also a built-in heatsink in the Raspberry Pi 400 that's not included with the SBC.

SEE: Raspberry Pi 4: Higher-quality, faster graphics edge closer with Vulkan support via Mesa

But the Raspberry Pi 400 isn't a device for hardware hackers. As Raspberry Pi notes in the user manual: "There are no user-serviceable parts inside Raspberry Pi 400, and opening the unit is likely to damage the product and will invalidate the warranty."

Full specifications for the Raspberry Pi 400 are:
Broadcom BCM2711 quad-core Cortex-A72 – Arm v8 – 64-bit SoC at 1.8GHz
4GB LPDDR4-3200
Dual-band – 2.4GHz and 5.0GHz – IEEE 802.11b/g/n/ac wireless LAN
Bluetooth 5.0, BLE
Gigabit Ethernet
Two × USB 3.0 and 1 × USB 2.0 ports
Horizontal 40-pin GPIO header
Two × micro HDMI ports – supporting up to 4Kp60
H.265 – 4Kp60 decode; H.264 – 1,080p60 decode, 1,080p30 encode; OpenGL ES 3.0 graphics
MicroSD card slot for operating system and data storage
78- or 79-key compact keyboard, depending on regional variant
5V DC via USB connector
Operating temperature: 0°C to +50°C ambient
Maximum dimensions 286mm × 122mm × 23mm

The Raspberry Pi 400 features a horizontal 40-pin GPIO header on the rear of the keyboard, so it's possible to add physical HAT extensions, such as a camera. Image: Raspberry Pi Trading

For $100 you get the Raspberry Pi 400 Personal Computer Kit, which includes the Raspberry Pi 400, a USB mouse and USB-C power supply, an SD card with Raspberry Pi OS pre-installed, a micro HDMI cable for the display, and a Raspberry Pi Beginner's Guide. Image: Raspberry Pi Trading

Ocado to acquire two robotics companies for $287m

By Emma Upshall
02 November 2020

Ocado has announced that it plans to buy two robotics companies – Kindred Systems and Haddington Dynamics – for a total of $287 million, in an effort to grow its business and accelerate delivery and innovation.

The acquisition will enhance Ocado’s robotic manipulation capabilities and accelerate the commercial delivery of grocery robotic picking for its Ocado Smart Platform (OSP) clients.

Ocado has agreed to purchase Kindred Systems, which designs, supplies and services advanced piece-picking robots for e-commerce and order fulfilment, for approximately $262 million.

Based in San Francisco and Toronto, Kindred Systems has around 90 employees who will join Ocado’s existing technology team. The company is expected to generate revenues of over $35 million in 2021, with Ocado planning to expand Kindred’s customer base and robot deployment in the USA and globally.

Meanwhile, Ocado will purchase Las Vegas-based Haddington Dynamics, a robotic-arm designer and manufacturer, for approximately $25 million.

The news came as Ocado raised its full-year profits expectations by 50%, as the group continues to see high demands with consumers moving to online grocery “in record numbers”.

“We consider the opportunities for robotic manipulation solutions to be significant, both for OSP clients and across the fast-growing online retail and logistics sectors,” said Tim Steiner, CEO of Ocado.

He added: “Ocado has made meaningful progress in developing the machine learning, computer vision and engineering systems required for the robotic picking solutions that are currently in production at our customer fulfilment centre in Erith. Given the market opportunity we want to accelerate the development of our systems, including improving their speed, accuracy, product range and economics.”

Both acquisitions are subject to customary conditions and are expected to close during calendar year 2020.

Magnitude 7.0 Earthquake Hits Turkey and Greece
The region has experienced 29 earthquakes with a magnitude of 6.0 or higher in the last 100 years

Search and rescue teams search for survivors in the debris of fallen buildings in Izmir, Turkey. (Photo by OZAN KOSE/AFP via Getty Images)

By Theresa Machemer
SMITHSONIANMAG.COM
NOVEMBER 2, 2020

On October 30, a 7.0 magnitude earthquake struck the eastern Aegean Sea between Turkey and Greece. The tremblor shook Izmir, Turkey, where it severely damaged 20 buildings. As of Monday, the death toll reached 91, including two teenagers in Greece, reports Al Jazeera.

Greece and western Turkey sit above a complicated convergence of chunks of Earth’s crust called tectonic plates. Four plates meet under the Aegean Sea, putting immense pressure on the plate directly below Turkey, Maya Wei-Haas reports for National Geographic. That makes the region one of the most geologically active in the world. It’s seen at least 29 earthquakes with magnitudes above 6.0 in the last century, Jariel Arvin reports for Vox. Last week’s earthquake has caused more than 900 aftershocks, 42 of which had a magnitude above 4.0, Isil Jariyuce and Maija Ehlinger report for CNN.

The complex geology of the region makes it difficult to study and predict its hazards, University of Leeds earthquake researcher Laura Gregory tells National Geographic. "There isn't one big fault that we can focus on, but instead many faults located over a huge area, most of which could cause a devastating earthquake," like the one on October 30, says Gregory through direct messages to National Geographic on Twitter.

When two massive slabs of Earth’s crust push, pull or slide against each other suddenly, earthquakes shake the surface. Modern buildings in earthquake-prone areas make use of construction techniques like base isolation to prepare for the natural disasters. In base isolation, the floor of a building is separated from its foundation, connected by strong but flexible isolators that allow the ground to shift underneath while the building wobbles above. But Izmir has many older buildings that aren’t equipped for quakes, the New York Times reports.

Turkey’s last earthquake of this scale happened in January, when a magnitude-6.8 earthquake killed more than 30 people in the eastern Elazig and Malatya provinces, BBC News reported at the time.

The region is so active because a trio of colliding plates are squeezing the Anatolian plate westward, almost like it “is being pushed out like a watermelon seed between two fingers,” University of Texas at Dallas tectonics expert Robert Stern tells National Geographic. At the same time, the African plate is diving below the western half of the Anatolian plate. That creates “slab suction,” University of Lisbon marine geologist Joao Duarte tells National Geographic. As one plate dips into the mantle, it drags everything above it along for the ride.

Friday’s earthquake was also followed by a small tsunami, per Vox, that flooded the streets of Izmir’s Seferihisar district.

Rescue teams are still searching for survivors in the rubble. One man, Oguz Demirkapi, was rescued after spending 30 minutes under 12 feet of debris, per the Times. He was in his third-floor apartment when the earthquake started, and he survived by curling up in a corner of the room while the building crumbled. Teams have also rescued a 70-year-old man after 34 hours under rubble, a three-year-old girl after more than 60 hours.

Murat Boz, who leads a civilian search and rescue team, tells the New York Times that rescue efforts would continue “nonstop, without a break, for 24 hours, day and night.”

Boz added, “We have experienced survival at the 187th hour of a previous earthquake. So if we take that as a benchmark, we are at the very beginning.”

Theresa Machemer is a freelance writer based in Washington DC. Her work has also appeared in National Geographic and SciShow. Website: tkmach.com

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Tuesday, November 03, 2020

Denisovan DNA found in sediments of Baishiya Karst Cave on Tibetan Plateau

Ocado to acquire two robotics companies for $287m

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