AKAKOR GEOGRAPHICAL EXPLORING

An international team of scientists led by Dr. Stephan Spiekman, Dr. Eudald Mujal and Prof. Dr. Rainer Schoch, paleontologists at the State Museum of Natural History Stuttgart, has re-examined the fossil of the reptile Trachelosaurus fischeri, which was first described at the beginning of the 20th century.

Comparisons with new fossil finds of a similar marine reptile from China show that Trachelosaurus fischeri is the world’s oldest long-necked marine reptile. The scientists have published their research findings on the 247-million-year-old fossil from Sachsen-Anhalt, Gemany, in the Swiss Journal of Palaeontology.

Trachelosaurus fischeri was already discovered back in the 19th century in layers of Buntsandstein (Middle Triassic) in Bernburg an der Saale, Germany, and it was subsequently added to the collection of Martin Luther University Halle-Wittenberg. The specimen is currently on loan to the State Museum of Natural History Stuttgart, where it was re-examined by specialists.

Trachelosaurus fischeri was first described in a publication in 1918, but controversy remained as to what kind of reptile this fossil actually represented. This is because Trachelosaurus fischeri has a unique anatomy, including an unusually large number of vertebrae, and because of the relatively poor preservation of the fossil: The skeleton is incomplete and its remains are scattered all over the rock in which it was preserved.

“Through research on Chinese fossils of the long-necked marine reptile Dinocephalosaurus, which I published with colleagues just a few weeks ago, we were able to solve the mystery of Trachelosaurus fischeri. The anatomy shows us that it is closely related to Dinocephalosaurus.

“Trachelosaurus fischeri is the first fossil of this reptile group to be found outside of China. It is also the oldest long-necked marine reptile known to date,” says Dr. Stephan Spiekman, an expert on this group of animals at the State Museum of Natural History Stuttgart.

After the great mass extinction at the Permian-Triassic boundary 252 million years ago, there was a very rapid diversification of new reptile species on both land and in the water at the beginning of the Triassic period. These included the first long-necked marine reptiles. How these complex evolutionary biological developments took place is an important subject of research.

The scientists suspect that Trachelosaurus fischeri was washed into a shallow water area 247 million years ago, as footprints of land-dwelling animals are also preserved on the rock in which the fossil is preserved.

For the researchers, the find and its re-evaluation are another step toward a better understanding of marine ecosystems at the beginning of the Triassic period. The history of the fossil shows the importance of historical museum and university collections for natural history research, emphasize the authors of the study.

New discoveries from various parts of the world regularly enable scientists to reinterpret what was already discovered many years, sometimes even centuries, ago and carefully being kept in museums.

Correcting 50-year-old errors in the math used to understand how electromagnetic waves scatter electrons trapped in Earth’s magnetic fields will lead to better protection for technology in space.

“The discovery of these errors will help scientists improve their models of artificial radiation belts produced by high-altitude nuclear explosions and how an event like that would impact our space technology,” said Greg Cunningham, a space scientist at Los Alamos National Laboratory. “This allows us to make better predictions of what that threat could be and the efficacy of radiation belt remediation strategies.”

Heliophysics models are important tools researchers use to understand phenomena around the Earth, such as how electrons can become trapped in the near-Earth space environment and damage electronics on space assets, or how Earth’s magnetic field shields us from both cosmic rays and particles in solar wind.

Cunningham is particularly interested in studying the Van Allen radiation belts because they provide a natural analog to artificial radiation belts that could occur after a high-altitude nuclear explosion.

“In an artificial radiation belt, electrons produced by a nuclear explosion can become trapped in the Earth’s magnetic field in the same way as naturally occurring radiation belts,” Cunningham said. “When these electrons become trapped in the inner radiation belt for many years, they could destroy existing satellites and make it impossible to deploy new ones.”

Researchers in the heliophysics community have long been using quasilinear theory, which explains plasma turbulence, to understand particle scattering. Simulation models based on the theory play an important role in understanding how to protect space technology.

But through his research, Cunningham tried to rederive papers based on quasilinear theory and discovered errors in the longstanding equation used across the space-physics community.

“In certain types of models, this error can really impact the answer you get; you can get orders of magnitude difference in the scattering rates,” Cunningham said. “Now, researchers who have written papers over the last 20 or 30 years can go back and take a look and see whether or not this affects their work.”

“The error went undiscovered for so long simply because the research community didn’t think the original authors, who are highly cited researchers in the field, could have made this mistake,” he added.

Cunningham’s paper detailing the errors was recently published in Journal of Geophysical Research: Space Physics.

UBC researchers believe a group of killer whales observed hunting marine mammals including sperm whales, as well as a sea turtle, in the open ocean off California and Oregon could be a new population.

Based on available evidence, the researchers posit in a new study published in Aquatic Mammals that the 49 orcas could belong to a subpopulation of transient killer whales or a unique oceanic population found in waters off the coast of California and Oregon.

“The open ocean is the largest habitat on our planet, and observations of killer whales in the high seas are rare,” said first author Josh McInnes, a master’s student at the UBC Institute for the Oceans and Fisheries (IOF). “In this case, we’re beginning to get a sense of killer whale movements in the open ocean and how their ecology and behavior differs from populations inhabiting coastal areas.”

Three ecotypes of killer whales live along the coasts of California and Oregon: ‘residents,’ ‘transients,’ and ‘offshores’.

The unknown orcas have been spotted before, but the new paper contains a weight of evidence gathered from nine encounters with 49 animals from 1997 to 2021, enough to form a solid hypothesis, the researchers said.

“It’s pretty unique to find a new population. It takes a long time to gather photos and observations to recognize that there’s something different about these killer whales,” said co-author Dr. Andrew Trites, IOF professor.

The 49 killer whales could not be matched with any known animals through photos or descriptions. “In one of the first encounters researchers had with a pod of these oceanic killer whales, they were observed taking on a herd of nine adult female sperm whales, eventually making off with one. It is the first time killer whales have been reported to attack sperm whales on the West Coast,” said McInnes.

“Other encounters include an attack on a pygmy sperm whale, predation on a northern elephant seal and Risso’s dolphin, and what appeared to be a post-meal lull after scavenging a leatherback turtle.”

Shark scars provide vital clues

A key clue to the new population’s presumed habitat range lies in cookie-cutter shark bite scars observed on almost all of the orcas. This parasitic shark lives in the open ocean, meaning the new population primarily inhabits deep waters far from land.

The orcas also feature physical differences from the three main ecotypes, including in their dorsal fins and saddle patches—the gray or white patches by the fin.

“While the sizes and shapes of the dorsal fins and saddle patches are similar to transient and offshore ecotypes, the shape of their fins varied, from pointed-like transients to rounded-like offshore killer whales,” said McInnes. “Their saddle patch patterns also differed, with some having large uniformly gray saddle patches and others having smooth narrow saddle patches similar to those seen in killer whales in tropical regions.”

Along with marine mammal stock assessment surveys, fishermen and passengers on an open-ocean birding expedition and whale-watching tour also provided observations of the unidentified killer whales, said Dr. Trites. Spotting the new population has become something of a hobby among fishermen, some of whom have bought cameras for their trips specifically to snap an encounter, the researchers said.

The researchers hope to document more sightings and gather more information, including acoustic data about the orcas’ calls and genetic information from DNA samples to investigate further how these killer whales may differ, or not, from already documented populations.

Researchers from China and Japan have discovered distinct characteristics of Earth’s lower mantle flow field. They investigated seismic anisotropy in the upper part of the lower mantle beneath the Philippine Sea Plate (PSP) and found that the ancient lower mantle flow field is still preserved there.

The lower mantle is an important layer of the Earth and may play an important role in the evolution and material cycling of Earth’s interior. It is generally believed to be not only the final destination of subducted slabs, but also the birthplace of mantle plumes, which are two major styles in the evolution and material cycling of the Earth’s surface and interior. However, our knowledge of the characteristics of the flow field and geodynamics of the lower mantle is still deficient.

In this study, the researchers performed P-wave azimuthal anisotropy tomography to image the 3D anisotropic structure of the crust and mantle down to a depth of 1,600 km beneath the PSP. The tomographic results show that N-S fast velocity directions (FVDs) exist at depths of 700–900 km below the mid-PSP. They also observed two isolated fast velocity anomalies with NW-SE FVDs at depths of 700–1,600 km beneath the PSP.

They found that the N-S FVDs at depths of 700–900 km are not related to the slab subduction, because they occur away from the present subduction zones. They are also independent of a mantle plume, as there has been no active mantle plume beneath the PSP since the early Cenozoic.

Based on previous geodynamic simulations and seismological results, the researchers inferred that the N-S FVDs at depths of 700–900 km reflect the remnant Pacific lower mantle flow field at about 50 Ma.

In addition, the two isolated fast velocity anomalies are consistent with seismic scatterers at depths of 1,000–1,800 km detected by previous seismological studies, and their locations are generally consistent with that of the spreading center between the Izanagi and Pacific plates when this spreading center was about to subduct beneath the Eurasian Plate. Thus, the isolated fast velocity anomalies are inferred to be remnants of the subducted Izanagi slab.

“The NW-SE FVDs in the two isolated fast anomalies are further inferred to reflect the Pacific lower mantle flow field at about 40 Ma, because the two isolated fast velocity anomalies are surrounded by amorphous mantle flow field and are not affected by the present lower mantle flow,” said Prof. Fan Jianke from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), first and corresponding author of the study.

“Our study shows that seismic anisotropy is more widespread in the lower mantle than previously thought,” said Prof. Fan. “These observations also provide important and independent seismic evidence for the existence of past deformation in the lower mantle, which can help us better understand the geodynamic properties of the lower mantle.”

April 17, 2021, was a day like any other day on the sun, until a brilliant flash erupted and an enormous cloud of solar material billowed away from our star. Such outbursts from the sun are not unusual, but this one was unusually widespread, hurling high-speed protons and electrons at velocities nearing the speed of light and striking several spacecraft across the inner solar system.

In fact, it was the first time such high-speed protons and electrons—called solar energetic particles (SEPs)—were observed by spacecraft at five different, well-separated locations between the sun and Earth as well as by spacecraft orbiting Mars. And now these diverse perspectives on the solar storm are revealing that different types of potentially dangerous SEPs can be blasted into space by different solar phenomena and in different directions, causing them to become widespread.

“SEPs can harm our technology, such as satellites, and disrupt GPS,” said Nina Dresing of the Department of Physics and Astronomy, University of Turku in Finland. “Also, humans in space or even on airplanes on polar routes can suffer harmful radiation during strong SEP events.”

Scientists like Dresing are eager to find out where these particles come from exactly—and what propels them to such high speeds—to better learn how to protect people and technology in harm’s way. Dresing led a team of scientists that analyzed what kinds of particles struck each spacecraft and when. The team published its results in the journal Astronomy & Astrophysics.

Currently on its way to Mercury, the BepiColombo spacecraft, a joint mission of ESA (the European Space Agency) and JAXA (Japan Aerospace Exploration Agency), was closest to the blast’s direct firing line and was pounded with the most intense particles. At the same time, NASA’s Parker Solar Probe and ESA’s Solar Orbiter were on opposite sides of the flare, but Parker Solar Probe was closer to the sun, so it took a harder hit than Solar Orbiter did.

Next in line was one of NASA’s two Solar Terrestrial Relations Observatory (STEREO) spacecraft, STEREO-A, followed by the NASA/ESA Solar and Heliospheric Observatory (SOHO) and NASA’s Wind spacecraft, which were closer to Earth and well away from the blast. Orbiting Mars, NASA’s MAVEN and ESA’s Mars Express spacecraft were the last to sense particles from the event.

Altogether, the particles were detected over 210 longitudinal degrees of space (almost two-thirds of the way around the sun)—which is a much wider angle than typically covered by solar outbursts. Plus, each spacecraft recorded a different flood of electrons and protons at its location. The differences in the arrival and characteristics of the particles recorded by the various spacecraft helped the scientists piece together when and under what conditions the SEPs were ejected into space.

These clues suggested to Dresing’s team that the SEPs were not blasted out by a single source all at once but propelled in different directions and at different times potentially by different types of solar eruptions.

“Multiple sources are likely contributing to this event, explaining its wide distribution,” said team member Georgia de Nolfo, a heliophysics research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Also, it appears that, for this event, protons and electrons may come from different sources.”

The team concluded that the electrons were likely driven into space quickly by the initial flash of light—a solar flare—while the protons were pushed along more slowly, likely by a shock wave from the cloud of solar material, or coronal mass ejection.

“This is not the first time that people have conjectured that electrons and protons have had different sources for their acceleration,” de Nolfo said. “This measurement was unique in that the multiple perspectives enabled scientists to separate the different processes better, to confirm that electrons and protons may originate from different processes.”

In addition to the flare and coronal mass ejection, spacecraft recorded four groups of radio bursts from the sun during the event, which could have been accompanied by four different particle blasts in different directions. This observation could help explain how the particles became so widespread.

“We had different distinct particle injection episodes—which went into significantly different directions—all contributing together to the widespread nature of the event,” Dressing said.

“This event was able to show how important multiple perspectives are in untangling the complexity of the event,” de Nolfo said.

These results show the promise of future NASA heliophysics missions that will use multiple spacecraft to study widespread phenomena, such as the Geospace Dynamics Constellation (GDC), SunRISE, PUNCH, and HelioSwarm. While single spacecraft can reveal conditions locally, multiple spacecraft orbiting in different locations provide deeper scientific insight and offer a more complete picture of what’s happening in space and around our home planet.

It also previews the work that will be done by future missions such as MUSE, IMAP, and ESCAPADE, which will study explosive solar events and the acceleration of particles into the solar system.