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Spatio-temporal evaluation of tropospheric delay products in China using CMONOC data as reference

Recent articles in Advances in Space Research - Thu, 03/20/2025 - 19:10

Publication date: 15 March 2025

Source: Advances in Space Research, Volume 75, Issue 6

Author(s): Zhuoyue Wen, Fei Yang, Jian Li, Ruixian Hao, Tianyang Liu, Zhuangzhuang Wang

Rapid sensing of atmospheric water vapor with timely service of the GNSS satellite clock error

Recent articles in Advances in Space Research - Thu, 03/20/2025 - 19:10

Publication date: 15 March 2025

Source: Advances in Space Research, Volume 75, Issue 6

Author(s): XiaoMing Li, HaoJun Li, Zhicheng Li

Earth's lungs are choking on plastic and smoke—scientists hope to unblock them

Phys.org: Earth science - Thu, 03/20/2025 - 16:17

A graph I saw in high school appeared to show the Earth breathing. It was a graph that plotted carbon dioxide in the atmosphere over the course of the 20th century and into the 21st. CO2 had risen steadily, and then more rapidly, but it hadn't gone up in a straight line. Each year it had fallen sharply before rising to a new peak, increasing over time in an upwards zig-zag.

NASA uses advanced radar to track groundwater in California

Phys.org: Earth science - Thu, 03/20/2025 - 16:12

Where California's towering Sierra Nevada surrenders to the sprawling San Joaquin Valley, a high-stakes detective story is unfolding. The culprit isn't a person but a process: the mysterious journey of snowmelt as it travels underground to replenish depleted groundwater reserves.

Fully AI-driven weather prediction system delivers accurate forecasts faster with less computing power

Phys.org: Earth science - Thu, 03/20/2025 - 16:00

A new AI weather prediction system, Aardvark Weather, can deliver accurate forecasts tens of times faster and using thousands of times less computing power than current AI and physics-based forecasting systems, according to research published in Nature.

Peatlands' carbon capture potential increases with rising temperatures

Phys.org: Earth science - Thu, 03/20/2025 - 15:45

According to a predictive model developed by a CNRS researcher and his European colleagues, the microalgae present in peat bogs could offset up to 14% of future CO2 emissions, thanks to their photosynthetic activity. This conclusion was reached by basing the work on in situ experiments and the various predictive scenarios established by the IPCC.

Scientists to explore why Everest glacier is so warm

Phys.org: Earth science - Thu, 03/20/2025 - 15:36

A team of researchers is making final preparations for a trip to Mount Everest in Nepal next month to explore why the ice of one of the mountain's most iconic glaciers is so close to the melting point.

First earthquakes detected in Pacific Ocean using ultra-stable optical interferometry on undersea cables

Phys.org: Earth science - Thu, 03/20/2025 - 13:57

NPL and MSL in New Zealand successfully detected a multitude of earthquakes in the Pacific Ocean using a pioneering detection technique.

Revoking EPA's endangerment finding won't be simple and could have unintended consequences

Phys.org: Earth science - Thu, 03/20/2025 - 13:49

Most of the United States' major climate regulations are underpinned by one important document: It's called the endangerment finding, and it concludes that greenhouse gas emissions are a threat to human health and welfare.

Q&A: Earth scientist discusses the shrinking waters of the Colorado River

Phys.org: Earth science - Thu, 03/20/2025 - 12:09

Key agreements in the "Law of the River," which encompasses more than 100 years of regulations, laws, court decisions and more focused on managing the Colorado River, are set to expire next year. First established in 1922 as the Colorado River Compact, the guidelines split water management and allocation among seven states.

Anisotropic tomography and seismotectonics of the central Tanlu fault zone in East China

Geophysical Journal International - Thu, 03/20/2025 - 00:00

SummaryWe determine detailed 3-D velocity and anisotropy models of the crust beneath the central segment of the Tanlu fault zone (TLFZ) in east China using hand-picked arrival times of direct waves (Pg, Sg), refracted waves (Pn, Sn), and the Moho reflected waves (PmP and SmS) of local earthquakes recorded at 55 portable seismic stations of our newly deployed TanluArray and 45 Chinese provincial stations. Our results show that the pattern of seismic velocity and anisotropy is in good agreement with surface geological and tectonic features in the study region. Along the TLFZ, obvious low-velocity (low-V) anomalies are visible in the lower crust in the north of the Cangni fault, whereas high-velocity (high-V) anomalies appear in the upper and middle crust. The 1668 Tancheng earthquake (M8.5) and small-to-moderate earthquakes occurred in the high-V zones but underlain by low-V anomalies. The low-V zones may reflect significant effects of fluids derived from hot and wet upwelling flow in the big mantle wedge. Under the Suqian seismic gap, low-V anomalies are clearly imaged in the middle crust, whereas high-V anomalies appear in the lower crust, suggesting the absence of fluids in the deep crust, which could explain why few earthquakes occurred there. The fast velocity direction (FVD) of P-wave azimuthal anisotropy changes with depth. The FVD is parallel with the TLFZ strike in the upper crust in and around the TLFZ, reflecting the strike-slip features of the fault zone. Our results provide new seismic constraints on the structure and tectonic evolution of the TLFZ.

Interseismic Deformation of the Húsavík-Flatey Fault (North Iceland) from two Decades of GNSS Data

Geophysical Journal International - Thu, 03/20/2025 - 00:00

SummaryThe Tjörnes Fracture Zone in North Iceland is one of two transform zones in Iceland capable of generating earthquakes of magnitude ∼7. More than 150 years have passed since the last two major earthquakes occurred on the Húsavík-Flatey fault, one of the two main transform structures within the Tjörnes Fracture Zone. Given the seismic hazard posed to Húsavík and adjacent coastal communities, accurately determining the slip rate and locking depth of this fault is crucial for a robust earthquake hazard and risk assessment. In this study, we significantly expand the existing GNSS dataset for the Tjörnes Fracture Zone by incorporating more than a decade of additional data and doubling the number of stations. This expansion not only improves the spatial coverage of the network, but also refines the station velocities. We present an updated interseismic velocity field for North Iceland and implement a backslip model with nine dislocation segments to describe the plate boundary deformation. Additionally, we include a point pressure source for the ongoing broad uplift signal in the study area. Our findings indicate a locking depth of $7.3\substack{+0.9 -0.7}$ km and an average slip rate of 6.9 ± 0.2 mm/yr for the Húsavík-Flatey fault. With our updated approach, we can narrow down model parameter constraints from previous studies and thereby provide an enhanced understanding of the earthquake potential of this region.