A study on the rotation of the Earth’s solid core confuses the mainstream media. Scientists of the Royal Observatory of Belgium clarify it

Earth Structure
Illustration Credit: Courtesy of Royal Observatory of Belgium

An article in Nature Geoscience on the rotation of the Earth’s core (more precisely its solid inner core) was recently published. However, the media have been misled by the press release of the science journal into thinking that the inner core stopped rotating or was even rotating in the opposite direction to that of the Earth surface, which is not the case at all. Scientists of the Royal Observatory of Belgium specialized in the rotation of the Earth and planets clarify the study and provide some information on the structure and rotation of the Earth.

Internal structure and rotation of the Earth

The interior of the Earth is divided into concentric layers. A few tens of kilometers below the surface begins the solid mantle, which extends to a depth of about 2900 km. Below that is the Earth’s core, which consists mainly of iron. The core is subdivided into an upper liquid layer down to a depth of about 5150 km and a central solid inner core with a radius of about 1220 km. The article in Nature Geoscience article is about the solid inner core.

The Earth revolves around its axis of rotation in 24 hours. Movements in the Earth’s atmosphere, hydrosphere and liquid core can cause small variations in the rotational period, so-called “length-of-day variations”, which can be on the order of milliseconds. The different layers that make up the Earth are linked by gravity and the frictional force and the electromagnetic force between the core and the solid parts. Therefore, the rotational period of the solid inner core can show small variations compared to the rotation of the mantle.

UNSW eco-friendly aviation research project receives CRC-P funding

Dr Branislav Hredzak and Professor John Fletcher have been awarded funding from Round 13 of the CRC Project scheme in collaboration with Dovetail Electric Aviation
Photo Credit: Dovetail Electric Aviation

An innovative UNSW research and development project focused on making regional commuter services greener and cheaper has been awarded a CRC-P grant.

Two UNSW Sydney researchers in collaboration with industry partners have been awarded $3 million in funding from the federal government’s Cooperative Research Centre Projects (CRC-P) program. This is part of a $12.8 million project that will convert a turboprop plane to electric propulsion, providing regional commuter services.

UNSW Senior Lecturer Dr Branislav Hredzak and Professor John Fletcher at the School of Electrical Engineering and Telecommunications secured the funding from Round 13 of the CRC Project scheme, for the project 'Electric Conversion to Fast Track Zero Emissions Commercial Aviation', together with Dovetail Electric Aviation, Sydney Seaplanes, Memko Aviation, Aerospace and Defense and CSIRO.

The project will develop, flight test and certify the conversion to electric propulsion of a turboprop aircraft, which will make regional commuter services eco-friendlier and more affordable with a focus on emissions-free aircraft for use on regional routes in the future.

Farming more seaweed for food, feed and fuel

Seaweed farmers in East Nusa Tenggara, Indonesia
Photo Credit: Eldo Rafael

A University of Queensland-led study has shown that expanding global seaweed farming could go a long way to addressing the planet’s food security, biodiversity loss and climate change challenges.

PhD Candidate Scott Spillias, from UQ’s School of Earth and Environmental Science, said seaweed offered a sustainable alternative to land-based agricultural expansion to meet the world’s growing need for food and materials.

“Seaweed has great commercial and environmental potential as a nutritious food and a building block for commercial products including animal feed, plastics, fibers, diesel and ethanol,” Mr. Spillias said.

“Our study found that expanding seaweed farming could help reduce demand for terrestrial crops and reduce global agricultural greenhouse gas emissions (GHG) by up to 2.6 billion tons of CO2-equivalent per year.”

Researchers mapped the potential of farming more of the 34 commercially important seaweed species using the Global Biosphere Management Model.

Kill Dates for Re-Exposed Black Mosses

Cape Rasmussen, one of the study sites mentioned in the paper.
Photo Credit: Derek J. Ford.

In their new paper for the Geological Society of America journal Geology, Dulcinea Groff and colleagues used radiocarbon ages (kill dates) of previously ice-entombed dead black mosses to reveal that glaciers advanced during three distinct phases in the northern Antarctic Peninsula over the past 1,500 years.

The terrestrial cryosphere and biosphere of the Antarctic Peninsula are changing rapidly as “first responders” to polar warming. We know from other studies that large glaciers of the Antarctic Peninsula are responding quickly to warmer summer air temperatures, and scientists have modeled that the glaciers expanded in the past because of cooler temperatures, and not increased precipitation. However, we know much less about how this plays out at sea level where ice, ocean, and sensitive coastal life interact. Knowing when glaciers advanced and retreated in the past would improve our understanding of biodiverse coastal ecosystems—thriving with seals, penguins, and plants—and their sensitivity in the Antarctic Peninsula. One of the limitations of reconstructing glacier history is that there are not that many types of terrestrial archives we can use to constrain past glacier behavior. Re-exposed dead plants, abandoned penguin colonies, and rocks can be dated to better know the timing of permanent snow or glacier advance in the past.

Rapid plant evolution may make coastal regions more susceptible to flooding and sea level rise

Brady Stiller, University of Notre Dame
Photo Credit: Courtesy University of Notre Dame

Evolution has occurred more rapidly than previously thought in the Chesapeake Bay wetlands, which may decrease the chance that coastal marshes can withstand future sea level rise, researchers at the University of Notre Dame and collaborators demonstrated in a recent publication in Science.

 Jason McLachlan, an associate professor in the Department of Biological Sciences, evaluated the role evolution plays in ecosystems in the Chesapeake Bay by studying a type of grass-like plant, Schoenoplectus americanus, also called chairmaker’s bulrush. The research team used a combination of historical seeds found in core sediment samples, modern plants, and computational models to demonstrate that “resurrected” plants were allocating more resources in their roots below ground, allowing them to store carbon more quickly than modern plants.

New virus discovered in whales, dolphins across the Pacific

Photo Credit: Richard Sagredo

A novel virus, potentially fatal to whales and dolphins, has been discovered by researchers at the University of Hawaiʻi Health and Stranding Lab. Prior to its discovery in 10 whale and dolphin host species across the Pacific, the virus was found in only a single marine mammal worldwide, a Longman’s beaked whale stranded on Maui in 2010. The findings were published in Frontiers in Marine Science.

The discovery of beaked whale circovirus (BWCV) in whales and dolphins expands the knowledge of marine mammal species that can become infected with the disease. Circoviruses are DNA viruses that cause disease in birds, pigs and dogs, and in severe cases can become fatal.

“Our study found Cuvier’s beaked whales tested positive for BWCV in Saipan and American Samoa, nearly 4,000 miles away from the first discovered case,” said Kristi West, director of the UH Health and Stranding Lab. “The positive cases found outside of Hawaiʻi were surprising, and indicates that this virus is spread across the Central and Western Pacific and may have a global presence in marine mammals.”

Small-scale octopus fisheries can provide sustainable source of vital nutrients for tropical coastal communities

Photo Credit: Blue Ventures

Research led by Cambridge scientists, and published in Nature Food, shows that tropical small-scale octopus fisheries offer a sustainable source of food and income to communities that face food insecurity, where the prevalence of undernourishment can exceed 40% and stunting in children under five commonly exceeds 30%. 

The high micronutrient density of octopus - including vitamin B12, copper, iron and selenium - means that human populations only need to eat a small quantity to supplement a diet primarily comprising staple plant crops. The new research shows that just a small amount of production in a tropical small-scale octopus fishery can deliver the micronutrient needs to a relatively large number of people.

The fast growth and adaptability of octopuses to environmental change can also facilitate sustainable production, and catch methods in the fisheries - primarily consisting of hand techniques, small-scale lines, pots and traps - are less environmentally harmful than those of large industrial fishing.

Health impact of chemicals in plastics is handed down two generations

UC Riverside mouse study finds paternal exposure to phthalates increases risk of metabolic diseases in progeny
Photo Credit: Meruyert Gonullu

Fathers exposed to chemicals in plastics can affect the metabolic health of their offspring for two generations, a University of California, Riverside, mouse study reports.

Plastics, which are now ubiquitous, contain endocrine disrupting chemicals, or EDCs, that have been linked to increased risk of many chronic diseases; parental exposure to EDCs, for example, has been shown to cause metabolic disorders, including obesity and diabetes, in the offspring.

Most studies have focused on the impact of maternal EDC exposure on the offspring’s health. The current study, published in the journal Environmental International, focused on the effects of paternal EDC exposure.

Led by Changcheng Zhou, a professor of biomedical sciences in the School of Medicine, the researchers investigated the impact of paternal exposure to a phthalate called dicyclohexyl phthalate, or DCHP, on the metabolic health of first generation (F1) and second generation (F2) offspring in mice. Phthalates are chemicals used to make plastics more durable.

Astronomers use novel technique to find starspots

Sunspots
Image Credit: HMI / SFLORG/ Via ESO Helioviewer

Astronomers have developed a powerful technique for identifying starspots, according to research presented this month at the 241st meeting of the American Astronomical Society, and published in the journal Monthly Notices of the Royal Astronomical Society

Our sun is at times dotted with sunspots, cool dark regions on the stellar surface generated by strong magnetic fields, which suppress churning motions and impede the free escape of light. "On other stars, these phenomena are called starspots," said Lyra Cao, lead author of the study and a graduate student in astronomy at The Ohio State University. 

“Our study is the first to precisely characterize the spottiness of stars and use it to directly test theories of stellar magnetism,” said Cao. “This technique is so precise and broadly applicable that it can become a powerful new tool in the study of stellar physics.”

Use of the technique will soon allow Cao and her colleagues to release a catalog of starspot and magnetic field measurements for more than 700,000 stars – increasing the number of these measurements available to scientists by three orders of magnitude.

Researchers Unveil New Collection of Human Brain Atlases that Chart Postnatal Development

Surface-volume atlases from 2 weeks to 24 months.
Image Credit: © 2023, Ahmad et al., CCBY 4.0

Led by Pew-Thian Yap, PhD, researchers at the UNC School of Medicine created monthly infant brain atlases to help researchers analyze the developing brain in detail to investigate neurological disorders and other conditions.

Human brain atlases can be used by medical professionals to track normative trends over time and to pinpoint crucial aspects of early brain development. By using these atlases, they are able to see what typical structural and functional development looks like, making it easier for them to spot the symptoms of abnormal development, such as attention-deficit / hyperactivity disorder (ADHD), dyslexia, and cerebral palsy.

Pew-Thian Yap, PhD, professor in the UNC Department of Radiology, and colleagues in the department and the Biomedical Research Imaging Center (BRIC) have created a new collection of month-by-month infant brain atlas (IBA) that capture fine spatiotemporal details of the early developing brain.