Abstract
The risk of earthquakes and their effects on both nature and infrastructure in seismically active regions of India require adaptable and scalable earthquake early warning (EEW) systems. Developing a robust EEW system is crucial to mitigate earthquake risks in the region, but it is a challenging task. Various institutes have attempted to develop EEW systems using different methods. Still, there is no common consensus, and issues remain with response time and reliability of disseminated information to the public. Efforts by institutions like the Indian Institute of Technology, Roorkee, have advanced EEW technologies, focusing on dense seismic sensor networks, real-time data processing algorithms, and effective dissemination mechanisms. Recent initiatives aim to improve sensor sensitivity and accuracy through fast communication systems for quicker earthquake detection. However, challenges persist in making EEW accessible and affordable, particularly in remote areas, due to the lack of a nationwide system. The National Centre for Seismology (NCS), under the Ministry of Earth Sciences (MoES), is piloting an EEW system in the NW Himalayas, which could lead to a nationwide implementation. Developing region-specific algorithms for rapid data analysis and nurturing collaboration between academic institutions, government agencies, and international partners are crucial steps. Public awareness campaigns and educational programs are essential for community resilience and timely response to earthquake alerts. Establishing a robust EEW system in India could significantly enhance earthquake risk mitigation efforts in earthquake-prone zones of the country and should be viewed within the context of a holistic risk reduction framework. EEW systems can enhance mitigation efforts, but they must be complemented by other essential measures, such as improving building resilience and promoting public awareness.
New Cornell University led-research challenges the long-standing belief that active volcanoes have large magma bodies that are expelled during eruptions and then dissipate over time as the volcanoes become dormant.
The state of Maine was hit by a rare 3.8 magnitude earthquake Monday morning, a tremor that could be felt across the New England region.
As we burn fossil fuels, the amount of carbon dioxide in Earth's atmosphere is gradually rising, and with it, the planet's average temperature. How fast the level of atmospheric carbon dioxide—and with it, the temperature—goes up matters for the ability of humans and ecosystems to adjust. A slower increase gives humans time to move away from low-lying areas and animals time to move to new habitats.
The rate of ocean warming has more than quadrupled over the past four decades, a new study has shown. Ocean temperatures were rising at about 0.06 degrees Celsius per decade in the late 1980s, but are now increasing at 0.27 degrees Celsius per decade.
SummaryDespite significant progress in paleomagnetic research over the last century, the origin, evolution, and long-term behavior of the geomagnetic field remains poorly understood. One significant open question is when and how the inner core nucleated. Since geomagnetic field behavior is intrinsically linked to the thermal evolution of the core, scientists have turned to the global paleointensity record to search for proxies for inner core nucleation. From this record, two signals have been identified as possible indicators of inner core nucleation: (1) A spike in magnetic field strength between 1.5–1.0 Ga, and (2) an initially strong, but gradually decreasing field strength that resulted in a weak dynamo in the Ediacaran. Although both these hypotheses are vastly different, they do have one common challenge hindering rigorous testing: A paucity of paleointensity data. This is especially true for the Precambrian time period for which well-preserved outcrops are scarce and weathering/alteration is nearly inescapable. Despite making up almost 90% of Earth's history, data from this super eon comprises <10% of the global paleointensity database. This lack of data for most of Earth's history represents a considerable gap in our knowledge and greatly impedes our ability to understand the origin and evolution of our planet and its magnetic field. In an effort to fill in this gap, we performed paleointensity experiments on Precambrian-aged mafic dikes from India (Malani Igneous Suite and Bastar, Dharwar, and Bundelkhand cratons) with ages ranging from ∼740 Ma to ∼2.36 Ga. To monitor thermal alteration and minimize the effects of non-ideal grain sizes, the Thellier method following the IZZI protocol was used. Successful results were obtained for samples from the Bundelkhand (∼740 Ma) and Bastar (∼1.89 Ga) cratons. The Bastar results fall in a ∼40 Myr gap in the database and corroborate field trends predicted by the Monte Carlo axial dipole moment model (MCADAM), which suggests that intensity values were moderately low (2–4 × 1022 Am2) in the middle Paleoproterozoic. The Bundelkhand result suggests that the field may have been rapidly decaying in the late Tonian to early Cryogenian.
The Arctic's "Last Ice Area" (LIA)—a vital habitat for ice-dependent species—might disappear within a decade after the central Arctic Ocean becomes ice-free in summer, which is expected to occur sometime around mid-century, a new study by McGill University researchers using a high-resolution model has found.
An interdisciplinary team of researchers from NTU Singapore, and Delft University of Technology (TU Delft), The Netherlands, has projected that if the rate of global CO2 emissions continues to increase and reaches a high emission scenario, sea levels would as a result very likely rise between 0.5 and 1.9 meters by 2100. The high end of this projection's range is 90 centimeters higher than the latest United Nations' global projection of 0.6 to 1.0 meters.
Publication date: Available online 22 January 2025
Source: Advances in Space Research
Author(s): Dieter Bilitza, Yong Ha Kim
Publication date: Available online 22 January 2025
Source: Advances in Space Research
Author(s): Marco Pietrella, Michael Pezzopane, Alessio Pignalberi, Carlo Marcocci, Massimo Viola, Emanuele Pica
Clouds, composed of tiny water droplets or ice crystals, play a vital role in regulating Earth's climate by influencing the amount of solar radiation that reaches the surface. The cloud phase significantly impacts the surface energy balance as liquid water clouds reflect more radiation than ice clouds.
Using a nearly 200-year record of lava chemistry from Kīlauea and Maunaloa, Earth scientists from the University of Hawai'i at Mānoa and colleagues revealed that Hawai'i's two most active volcanoes share a source of magma within the Hawaiian plume. Their discovery was published recently in the Journal of Petrology.
A study reveals that fire emissions in the Amazon and Cerrado are largely driven by the smoldering combustion of woody debris. This crucial discovery highlights the significant influence of fuel characteristics on fire emissions, with wide-ranging implications for global carbon cycles, air quality and biodiversity.
There's often little warning when a tsunami strikes, but a research team at USF aims to improve the forecasting of these hazardous events for communities that are most at risk.
The Earth's surface is constantly reshaped by the movement of tectonic plates, which make up the continental crust on which we are living. These tectonic plates are in continuous motion, and when one plate is pushed under another, it is called "subduction." These processes play a crucial role in shaping the Earth's landmasses, including the islands of Japan, over several hundred million years.
Author(s): Andrey M. Lipaev, Vadim N. Naumkin, Sergey A. Khrapak, Alexandr D. Usachev, Oleg F. Petrov, Markus H. Thoma, Michael Kretschmer, Cheng-Ran Du, Oleg D. Kononenko, and Andrey V. Zobnin
An analysis of lattice wave spectra in a three-dimensional dusty plasma structure formed in a direct current gas discharge with alternating polarity under microgravity conditions is reported. The spectra are determined using the Fourier transform of microparticle velocities, measured by tracking mic…
[Phys. Rev. E 111, 015209] Published Mon Jan 27, 2025
SummarySite-specific Probabilistic Tsunami Hazard Assessment (PTHA) is a powerful tool for coastal planning against tsunami risk. However, its typically high computational demands led to the introduction of a Monte Carlo Stratified Importance Sampling (SIS) approach, which selects a representative subset of scenarios for numerical inundation simulations. We here empirically validate this sampling approach, for the first time to our knowledge, using an existing extensive dataset of numerical inundation simulations for two coastal sites in the Mediterranean Sea (Catania and Siracusa, both located in Sicily, Italy). Moreover, we propose a modified importance sampling function to prioritise seismic tsunami scenarios based on their arrival time at an offshore point near the target site, in addition to their wave amplitude and occurrence rate as leveraged in the previous work. This sampling function is applied separately in each earthquake magnitude bin, and allows denser sampling of near-field earthquakes to whose variations tsunamis are very sensitive. We compare the confidence intervals of the offshore PTHA estimates obtained with the new and the original importance sampling functions. Then, we benchmark our onshore PTHA estimates obtained with both functions against the inundation PTHA calculated using the full set of scenarios. We also test the assumption that onshore random errors follow a normal distribution, as found previously for the offshore case. As a result of the benchmarks, we find that the SIS approach works satisfactorily. Introducing the arrival time as an additional sampling factor enhances the precision of the estimates of both the mean and the percentiles for the two coastal sites considered. With this modification it is possible to deal efficiently with heterogeneous near-field earthquake sources involving coastal deformation at Catania and Siracusa, in addition to regional crustal and subduction sources. By comparing the sampling errors with the model (epistemic) uncertainty, an optimal trade-off between the number of simulations employed and the uncertainty of the PTHA model can be found, even for such a complex situation. A relatively small number of scenarios, on the order of a few thousand, is sufficient to perform site-specific PTHA for practical applications. These numbers correspond to 4–8% of the already reduced ensembles used in previous assessments at the same sites.
SummaryThe Pamir tectonic zone originates from the intense collision of the Indo-Eurasian plate. Identifying the faults in the Pamir region region is essential for elucidating the collision mechanism and seismic characteristics. This paper compares the effect of the two-dimensional discrete wavelet transform (DWT2D) and the non-subsampled shearlet transform (NSST) on gravity field separation through synthetic model gravity field experiments. The results show that NSST can avoid the Gibbs phenomenon of DWT2D and better maintain the gravity field distribution. The surface gravity disturbances data of the Global Gravity Model Plus (GGMplus) with a high-spatial resolution (7.2 arcsec or approximately 200 m) is employed to separate the region-residual gravity fields in the neighbouring domain of the Pamir region based on the NSST. Furthermore, the gravity gradient tensor (GGT) is computed, and the correspondence between the GGT and the location and strike of the surrounding faults is analyzed. The results show that the GGT component and its various combinations can effectively identify shallow and deep faults, the residual field GGT and its combinations can effectively identify the distribution and direction of shallow faults, and the regional field GGT and its combinations can effectively identify the distribution and direction of deep faults. The existence of north-south trending faults in the Pamir-Hindu Kush region is widely accepted. However, our study has revealed an east-west trending concealed fault in the deep areas of the Hindu Kush (Depth > 200 km). This finding provides significant insights for studying the bidirectional subduction of the Indian and Eurasian plates. This research not only helps us to analyze the tectonic characteristics of the shallow and deep parts of the region separately but also provides complementary information for investigating the distribution of deep underground faults, especially when fault inversion of intermediate to deep source earthquakes is limited by factors such as uncertainty in source depth and complexity of seismic wave velocities.
SummaryIn Pakistan, the relative displacement between the Indian and Eurasian plates is accommodated by a left lateral transpression zone comprising the Chaman and Ghazaband faults and the Sulaiman Range. The current tectonic deformation of the Sulaiman Range is known only from some focal mechanisms and a few neotectonic studies. In this study, we propose an InSAR quantification of current tectonic deformation using the Sentinel 1 satellite. Velocity maps for the ascending and descending tracks enabled us to locate active faults affected by creep: the Harnaï and Kingri strike-slip faults, and the Gwal-Bagh thrust. We propose a numerical simulation that considers these faults as well as the level of detachment fold-and-thrust belt. Our results suggest the existence of out-of-sequence deformation along the Gwal-Bagh thrust, creep along the Harnaï and Kingri strike-slip faults, and slip along the décollement of the Sulaiman Range. The eastern part of the Sulaiman Range is characterized by a partitioning of the deformation with a left lateral strike-slip along the N170° Kingri fault and an eastward thrust. In contrast, the western part is characterized by north-south compressive deformation associated with right lateral strike-slip on the Harnaï N120° fault. Modelling of the co-seismic deformation of the 21 October 2021 earthquake shows that this earthquake occurred on a fault with a ramp geometry but affected by a strike-slip motion.
Abstract
The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) was proposed to the Chinese Academy of Science (CAS) and the European Space Agency (ESA) following a joint call for science missions issued in January 2015. SMILE was proposed by a team of European and Chinese scientists, led by two mission Co-PIs, one from China and one from Europe. SMILE was selected in June 2015, and its budget adopted by the Chinese Academy of Sciences in November 2016 and the ESA Science Programme Committee in March 2019, respectively. SMILE will investigate the connection between the Sun and the Earth using a new technique that will image the magnetopause and polar cusps: the key regions where the solar wind impinges on Earth’s magnetic field. Simultaneously, SMILE will image the auroras borealis in an ultraviolet waveband, providing long-duration continuous observations of the northern polar regions. In addition, the ion and magnetic field characteristics of the magnetospheric lobes, magnetosheath and solar wind will be measured by the in-situ instrument package. Here, we present the science goals, instruments and planned orbit. In addition the Working Groups that are supporting the preparation of the mission and the coordination with other magnetospheric missions are described.
