A first-of-its-kind study led by William & Mary's Batten School & VIMS is predicting estuaries along the East Coast of the U.S. will experience marine heat wave conditions for up to a third of the year by the end of the century. With estuaries serving as important nursery habitats for nearly 75% of all fish species and supporting more than 54 million jobs, this could have devastating consequences for marine ecosystems as well as the fisheries and communities that depend on them.
Publication date: Available online 24 February 2025
Source: Advances in Space Research
Author(s): Yuehao Teng, Bo Xu, Youtao Gao, Chaoyong Hu, Xin Li, Yang Liu
Publication date: Available online 24 February 2025
Source: Advances in Space Research
Author(s): Mohamed Abdel-Sabour, Mohamed I. Nouh, Essam Elkholy, Amr I. Basuny
Publication date: Available online 24 February 2025
Source: Advances in Space Research
Author(s): Jianhui Liu, Shirong Ye, Fengyu Xia, Pengzhi Wei, Yongzhao Fan, Yezhi Song
A swarm of earth tremors and fears of volcanic eruptions in January forced tens of thousands of people to move away from Awash Fentale, an area in the Afar region of Ethiopia. The area falls within a geologically active region of the Great Rift Valley that has experienced a number of earthquakes and volcanic events in the last 800 years. Two major volcanic eruptions occurred in 1250 and 1820 AD.
A new study published in Advances in Atmospheric Sciences sheds light on the complex relationship between methane emissions and the recovery of the stratospheric ozone layer. The research underscores how future increases in methane emissions could significantly influence ozone recovery, particularly in the polar regions.
At first glance, landscapes like the Great Plains and the Rockies may seem unchanging, but over geological time scales, they're dynamic systems. Plate tectonics raise mountains, while erosion—driven by glaciers, rain and wind—wears them down. But there's an often-overlooked factor in this process: the rock itself.
A new seismic study of Singapore could guide urban growth and renewable energy development in the coastal city nation, where 5.6 million residents live within an area of 734 square kilometers.
Some parts of Hawaii are sinking faster than others. That discovery, published in Communications Earth & Environment by researchers at the University of Hawaii (UH) at Mānoa, also highlights that as sea level rises, the infrastructure, businesses, and communities in these low-lying areas are at risk of flooding sooner than scientists anticipated, particularly in certain urban areas of O'ahu.
Hydrothermal alteration is a complex geological process that can later serve as an indicator of gold deposits for mineral explorers. The process sees hot and metal-rich fluids interact with surrounding rocks, causing chemical and mineralogical changes.
A type of artificial intelligence that mimics the functioning of the human brain could represent a powerful solution in automatically detecting wildfires, plummeting the time needed to mitigate their devastating effects, a new study finds.
Author(s): Louis Jose, James C. Welch, III, Timothy D. Tharp, and Scott D. Baalrud
Strongly magnetized plasmas, characterized by having a gyrofrequency larger than the plasma frequency (β=ωc/ωp≫1), are known to exhibit novel transport properties. Previous works studying pure electron plasmas have shown that strong magnetization significantly inhibits energy exchange between parall…
[Phys. Rev. E 111, 035201] Published Thu Mar 06, 2025
SummaryThe Central African Plateau records multiple stages of continental extension and assembly between the Congo and Kalahari cratons in south-central Africa. Of significant interest is the formation of the Neoproterozoic Katangan Basin which was subsequently closed during the Pan-African assembly of Gondwana — a region that contains some of the world’s largest sediment-hosted copper and cobalt deposits. Whether Katangan Basin development only involved continental extension or progressed to incipient sea-floor spreading is uncertain; so too the extent to which mafic magmatism has modified bulk-crustal structure. Also debated is whether crustal re-working during overprinting by the Pan-African Orogeny to form the Lufilian Arc, was localised or broadly distributed across the entire Katangan Basin. To address these questions, we calculate crustal thickness (H) and bulk-crustal VP/VS ratio (κ) using H-κ stacking of teleseismic receiver functions recorded by seismograph networks situated across the Central African Plateau, including the new Copper Basin Exploration Science (CuBES) network. Crustal thickness is 45–48 km below the Congo Craton margin, Mesoproterozoic Irumide belt, and Domes region of the Lufilian Arc, 38–42 km below the Bangweulu Craton and 35–40 km below the Pan-African Zambezi Belt in southeastern Zambia. Bulk-crustal VP/VS is generally low (<1.76) across the majority of the Plateau, indicating a dominantly felsic bulk-crustal composition. The formation of the Katangan Basin in the Neoproterozoic is thus unlikely to have been accompanied by voluminous mafic magmatism, significant lower crustal intrusions and/or the formation of oceanic crust. The early-Paleozoic overprinting of the basin by the Pan-African Orogeny, forming the Lufilian Arc, appears to have been most intense in the Domes region, where a deep and highly variable (38–48 km) Moho topography at short length-scales (<100 km), is evident in our H-κ stacking results. In contrast, shallow and flat Moho architecture with consistently low bulk crustal VP/VS ratios, are observed further south. This flat region includes the Mwembeshi Shear Zone, which is also not associated with a VP/VS ratio contrast, suggesting the fault likely separates two very similar crustal domains.
SummaryEarthquake cycle modelling is critical to help us understand the underlying physical mechanisms of earthquake processes. However, it is a very challenging scientific problem because of the variety of spatial and temporal scales involved in fault friction behaviour. Scholars have researched this problem based on different numerical methods, but there is still an urgent need to develop more rigorous and robust numerical methods. We construct a new finite-difference operator to approximate the variable-coefficient second derivatives by combining the central-difference method with the equivalent medium parametrisation method. Using the method of manufactured solutions, we perform rigorous convergence tests, and the results show that the new finite-difference operator achieves second-order convergence. We use this new method in 2D earthquake cycle simulation and the geometric multi-grid method as an iterative solver to accelerate the computation while optimising the code on a GPU platform to improve computational efficiency further. We simulate the earthquake sequences on a vertical fault in homogeneous and heterogeneous basin models using our method and SCycle, respectively. The comparison of results shows good agreement. Our method can be utilised to study the long-term slip histories of large-scale faults in complicated mediums, as demonstrated by these results.
SummaryAs seismic imaging moves towards the imaging of more complex media, properly modelling elastic effects in the subsurface is becoming of increasing interest. In this context, elastic wave conversion, where acoustic, pressure (P-) waves are converted into elastic, shear (S-) waves, is of great importance. Accounting for these wave conversions, in the framework of forward and inverse modelling of elastic waves, is crucial to creating accurate images of the subsurface in complex media. The underlying mechanism of wave conversion is well understood and described by the Zoeppritz equations. However, as these equations are highly non-linear, approximations are commonly used. The most well-known of these approximations is Shuey’s approximation. However, this approximation only holds for small angles and small contrasts, making it insufficient for realistic forward and inverse modelling scenarios, where angles and contrasts may be large. In this paper we present a novel set of approximations, based on Taylor expansions of the Zoeppritz equations, which we name the extended Shuey approximations. We examine the quality of these approximations to the Zoeppritz equations and compare them to existing approximations described in literature. We then apply these extended Shuey approximations to the elastic Full-Wavefield Modelling algorithm for a simple, synthetic, 1.5D example, where we show that we can accurately model the P- and S-wavefields in a forward modelling case. Finally, we apply our approximations to the elastic Full-Wavefield Migration algorithm for a simple, synthetic, 1.5D example, where we show that we can recover an accurate image in an inverse modelling case.
Whether it's rivers cutting through earth, lava melting through rock, or water slicing through ice, channels all twist and bend in a seemingly similar back-and-forth manner. But a new study led by scientists at The University of Texas at Austin has discovered that channels carved by rivers actually have curves distinct to those cut by lava or ice.
Iron oxide minerals are found in rocks around the globe. Some are magnetic, and some of them rust—especially when exposed to water and oxygen. These characteristics provide clues about the history of these minerals.
Е.Н. Овчинникова, А.П. Орешко, В.Е. Дмитриенко
Даётся обзор недавних работ, в которых изучается интерференция нескольких каналов рассеяния синхротронного излучения с длинами волн вблизи краёв поглощения атомов в кристаллах. Рассматриваются экспериментальные условия и теоретические подходы, обеспечивающие возможность разделения вкладов в интенсивность брэгговских отражений от разных видов рассеяния, приводятся конкретные примеры исследований и обсуждается роль интерференции. Показано, что получаемые результаты дают уникальную информацию о различных видах упорядочения (структурных, зарядовых, магнитных и др.) на атомном уровне и их динамическом поведении при внешних воздействиях.
On the abyssal plains, at depths between 3,000 and 6,000 meters, polymetallic nodules are scattered across millions of square kilometers, much like potatoes in a field. These mineral ores are formed over millions of years from metals dissolved in the ocean water or released during microbial degradation of organic material in the sediments. As global demand for critical metals, such as nickel, cobalt, and copper, grows, so too does the pressure to exploit these resources economically.
A new MIT-led study confirms that the Antarctic ozone layer is healing, as a direct result of global efforts to reduce ozone-depleting substances.
