Phys.org: Earth science

Cities are rapidly becoming the defining residential space of human life. Over 55% of the global population lived in urban areas in 2018, a proportion projected to reach nearly 68% by 2050, according to the United Nations (UN).

Greenland's largest glacier, Jakobshavn Glacier, may be edging closer to a critical threshold as meltwater runoff from the Greenland Ice Sheet accelerates in ways not seen in over a century, according to new research published in Climate of the Past. The study reconstructs more than 100 years of freshwater discharge flowing from the ice sheet into Disko Bay in western Greenland, revealing a striking and sustained change that began in the early 2000s.

Sea level can temporarily change for a variety of reasons—atmospheric pressure shifts and water accumulation from wind and storms, for example—which can cause flooding in coastal communities and affect maritime industry operations. The key to mitigating the effects of short-term sea level variation is accurate prediction that provides ample warning time to affected areas.

Cyanobacteria, as they still exist today, were the first organisms to carry out photosynthesis and release oxygen. Produced in primeval oceans about 2.5 billion years ago, this oxygen accumulated in Earth's atmosphere on an immense scale. A research team led by University of Tübingen geomicrobiologist Professor Andreas Kappler has used laboratory experiments to investigate how this process was even possible, given that the iron dissolved in ocean water strongly inhibited the growth of cyanobacteria.

For scientists who study the Southern Ocean, a long-standing silver lining in the gloomy forecast of climate change has been the theory of iron fertilization. As temperatures rise and glaciers in Antarctica melt, ice-trapped iron would feed blooms of microscopic algae, pulling heat-trapping carbon dioxide from the atmosphere as they grow. There's just one problem: The theory doesn't hold water.

We know Aotearoa New Zealand is home to many geographically and biologically special features. Yet few of us know it also has its very own measure of "deep time." Known as the New Zealand Geological Timescale, it has just undergone its most comprehensive revision in 20 years.

Climate change is having a profound impact on the Arctic. We know that the region is warming significantly faster than the global average, resulting in the melting of sea ice and disrupted habitats.

Eastern Canada has seen a rise in the number of hurricane- and near-hurricane strength events battering its maritime areas, with particularly violent storms in 2003 (Hurricane Juan), 2019 (Dorian) and 2022 (Fiona). While this seems to be a recent phenomenon, the region has experienced this kind of surge in activity before, according to a new Concordia University study.

Beaver dams are critical to river health and a source of biodiversity. They create wetlands, slow water and improve water quality. They also reduce flood peaks and delay runoff. But beaver dams are often blamed when extreme rainstorms cause flooding—especially when they fail.

A new study has identified a distinct climate precursor in the Mediterranean Sea that can predict winter precipitation levels in the Levant months in advance. The study, published in Weather and Climate Dynamics, is titled "Mediterranean Sea heat uptake variability as a precursor to winter precipitation in the Levant."

Hike north on the Appalachian Trail and the scenery slowly transforms. Rugged, steep ridgelines in Tennessee and Virginia soften into the broad summits and smooth peaks of Pennsylvania and New Jersey. According to new research from William & Mary Assistant Professor of Geology Joanmarie Del Vecchio, this contrast speaks to an ancient past.

The Great Unconformity is a major gap in Earth's geologic record. The missing layer between Precambrian and Cambrian rocks represents a gap of around a billion years of history. Among much debate surrounding the cause of the gap, a new study, published in the Proceedings of the National Academy of Sciences, indicates that the timing of the erosion leading to the Great Unconformity aligns with the assembly of the Columbia supercontinent, and that glaciation only contributed minimally.

Highly detailed 3D scans of dense tropical rain forest plots are enabling precise estimates of tree structure, volume and stored carbon, as part of a first-of-its-kind pilot initiative, led by UCL researchers. Published in the journal Earth System Science Data, the finalized full dataset of the 3D tree census is helping scientists better understand how much biomass (or plant material) forests contain, an important step in understanding how much carbon is stored across the entire forest.

For the first time, researchers have observed and measured weak electrical discharges, known as coronae, on trees during thunderstorms. A new study describes the near-invisible sparkles appearing similarly on branches of several tree species up and down the U.S. East Coast during the summer of 2024, implying that thunderstorms may paint entire canopies with a scintillating blue glow, albeit too faintly for human eyes to see.

A team of scientists led by the German Center for Integrative Biodiversity Research (iDiv), the Helmholtz Center for Environmental Research (UFZ), and Leipzig University has developed a new method to track Earth's greenness—a key indicator of vegetation health and activity—by calculating its center of mass.

Volcanoes and wildfires can inject millions of tons of gases and aerosol particles into the air, affecting temperatures on a global scale. But picking out the specific impact of individual events against a background of many contributing factors is like listening for one person's voice from across a crowded concourse. MIT scientists now have a way to quiet the noise and identify the specific signal of wildfires and volcanic eruptions, including their effects on Earth's global atmospheric temperatures.

A key question in any discussion about climate is "How much rain fell?" But perhaps there is an even more important one. Like any household budget, the global water economy is based on "income," that is, water entering the system as precipitation, and "expenditure"—water leaving the system through various forms of evaporation. On land, water evaporates mainly through vegetation, in a process known as evapo-transpiration.

The extraction of gas and oil by fracking—large-scale fracturing of underground rocks by injecting water, sand and additives—is generating growing concern in Argentine Patagonia. Neuquén province—home to the country's largest hydrocarbon reserves—has experienced an increase in earthquakes since fracking operations began there in 2015.

Thick cloud cover can completely obscure the surface of the Earth from satellite view, while thinner haze and shadows distort the image of rural and urban regions. As such, many remote sensing images for monitoring climate, crops, and urban growth are only partially usable.

Several studies have predicted that not all geomagnetic reversals have been discovered, but it was unknown in which periods they might be hidden. Researchers led by the National Institute of Polar Research used a statistical method called adaptive kernel density estimation to model the frequency of geomagnetic reversals at high temporal resolution. Based on the model, they proposed that undiscovered reversals may be hidden in four periods after the Cretaceous Normal Superchron.