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A differential search algorithm (DSA) application, which is a metaheuristic inspired by nature, for total field aeromagnetic data caused by volcanoes over a 2D dipping dyke is presented. Inversion of the total magnetic anomalies was performed by adding the background level in addition to the parameters of the dyke model (e.g., dip angle, the depth to the top, half-width, the distance from the origin to the reference point, and amplitude coefficient), which are often tried to be estimated in the literature studies. In synthetic dyke models, the efficiency of the DSA in parameter estimation of theoretically generated magnetic anomalies that do not contain noise and contain random noise at different levels has been demonstrated. Firstly, in the synthetic dyke model, the efficiency of the DSA in parameter estimation of theoretically generated noise-free magnetic anomaly is demonstrated. Additionally, different levels of random noise were added to the same synthetic model anomaly to test the performance of the algorithm in case the data contained noise. The results of the inversion show that the model parameters estimated from the DSA agree well with the correct ones. This fit was also statistically checked by calculating the probability density function. In the real case, the inversion approach was then used to interpret five prominent total aeromagnetic anomalies over the well-known Kula volcanic field located in western Türkiye. The depths and widths of these magmatic bodies lying underneath these volcanic cones are about 450 m and 470 m, respectively.

Monogenetic volcanism produces small-volume volcanoes with a wide range of eruptive styles, lithological features and geomorphic architectures. They are classified as spatter cones, scoria (or cinder) cones, tuff rings, maars (maar–diatremes) and tuff cones based on the magma/water ratio, dominant eruption styles and their typical surface morphotypes. The common interplay between internal, such as the physical–chemical characteristics of magma, and external parameters, such as groundwater flow, substrate characteristics or topography, plays an important role in creating small-volume volcanoes with diverse architectures, which can give the impression of complexity and of similarities to large-volume polygenetic volcanoes. In spite of this volcanic facies complexity, we defend the term “monogenetic volcano” and highlight the term’s value, especially to express volcano morphotypes. This study defines a monogenetic volcano, a volcanic edifice with a small cumulative volume (typically ≤1 km 3 ) that has been built up by one continuous, or many discontinuous, small eruptions fed from one or multiple magma batches. This definition provides a reasonable explanation of the recently recognized chemical diversities of this type of volcanism.

Most of the world’s 1500 active volcanoes are not instrumentally monitored, resulting in deadly eruptions which can occur without observation of precursory activity. The new Sentinel missions are now providing freely available imagery with unprecedented spatial and temporal resolutions, with payloads allowing for a comprehensive monitoring of volcanic hazards. We here present the volcano monitoring platform MOUNTS (Monitoring Unrest from Space), which aims for global monitoring, using multisensor satellite-based imagery (Sentinel-1 Synthetic Aperture Radar SAR, Sentinel-2 Short-Wave InfraRed SWIR, Sentinel-5P TROPOMI), ground-based seismic data (GEOFON and USGS global earthquake catalogues), and artificial intelligence (AI) to assist monitoring tasks. It provides near-real-time access to surface deformation, heat anomalies, SO2 gas emissions, and local seismicity at a number of volcanoes around the globe, providing support to both scientific and operational communities for volcanic risk assessment. Results are visualized on an open-access website where both geocoded images and time series of relevant parameters are provided, allowing for a comprehensive understanding of the temporal evolution of volcanic activity and eruptive products. We further demonstrate that AI can play a key role in such monitoring frameworks. Here we design and train a Convolutional Neural Network (CNN) on synthetically generated interferograms, to operationally detect strong deformation (e.g., related to dyke intrusions), in the real interferograms produced by MOUNTS. The utility of this interdisciplinary approach is illustrated through a number of recent eruptions (Erta Ale 2017, Fuego 2018, Kilauea 2018, Anak Krakatau 2018, Ambrym 2018, and Piton de la Fournaise 2018–2019). We show how exploiting multiple sensors allows for assessment of a variety of volcanic processes in various climatic settings, ranging from subsurface magma intrusion, to surface eruptive deposit emplacement, pre/syn-eruptive morphological changes, and gas propagation into the atmosphere. The data processed by MOUNTS is providing insights into eruptive precursors and eruptive dynamics of these volcanoes, and is sharpening our understanding of how the integration of multiparametric datasets can help better monitor volcanic hazards.

The Ulanhada Volcano Group is located in Inner Mongolia, China. It is an important Quaternary volcanic geological relic with different types of volcanic cones, craters, lava platforms, and other structures. Ground penetrating radar (GPR) can play an important role in volcanic exploration. We used pulse EKKO radar combined with 100MHz and 250MHz antennas to detect the No.1 Redhill volcanic. The results indicate that there are significant differences in reflection characteristics in radargrams of different frequencies, which can be used to analyze the material composition, eruption period, and stratigraphic coverage relationship of volcanic eruptions. At the same time, an accurate analysis of the region will also be used as an evaluation basis for the field scientific verification experiments of China’s Asteroid Core Scan Radar (ACSR) and Lunar Penetrating Radar (LPR).

The Pleiades Volcanic Field is made up of some 20 monogenetic, partly overlapping scoria and spatter cones, erupted in the last 900 ka, cropping out from the ice close to the head of the Mariner Glacier in northern Victoria Land, Antarctica. Erupted products vary from hawaiite to trachyte, defining a complete mild Na‐alkaline differentiation trend. Mafic samples are characterized by multi‐elemental patterns typical of OIB magmas, moderately low 87Sr/86Sr (0.7037) and high 143Nd/144Nd (0.51284), with a clear within‐plate affinity, indicating a subcontinental lithospheric source. With increasing SiO2, 87Sr/86Sr ratios increase up to 0.7052 and 143Nd/144Nd decrease to 0.51277, supporting the hypothesis of open‐system evolution, with significant crustal assimilation during fractional crystallization. The erupted volume of most evolved products (∼7 km3), according to fractionation models, suggests that primitive magmas should have been more than 10 times larger, indicating the occurrence of a large magma plumbing system, unexpected for a volcanic field of monogenetic scoria cones. The occurrence of a complete fractionation trend with large magma chambers and large assimilation rate is unusual, if not unique, among the alkali basaltic volcanic fields and it is matched by a climax of activity during the last glacial maximum (30 ka), as indicated by new 40Ar‐39Ar ages (30 ± 3 ka and 25 ± 2 ka) for samples from the two most prominent edifices. Therefore, we hypothesize a role of a thick ice cap in suppressing eruptions and ultimately leading to prolonged magma residence time in the subsurface, favoring significant fractionation coupled with unusual high rates of crustal assimilation. Plain Language Summary The Pleiades volcanic field is made up of some 20 monogenetic scoria and spatter cones, which erupted in the last 900 ka close to the head of the Mariner Glacier in northern Victoria Land, Antarctica. The erupted products are very unusual for alkali basaltic volcanism: indeed, whereas few samples show clear within‐plate subcontinental lithospheric characteristics and were directly derived from the mantle source, most of the products formed after extensive fractional crystallization matched by significant crustal assimilation, implying that primitive magma volumes are 10 times larger than outcropping products in an unusually large magma plumbing system. These peculiar features coincided with a climax of activity during the last glacial maximum (30–25 ka). Therefore, we speculate that a thick ice cap favored high rates of crystal fractionation coupled with crustal assimilation and was responsible for increasing magma residence times in chambers at crustal depths and suppressing the eruptive potential of magmas. Key Points The Pleiades complex (NVL, Antarctica) is made up of some 20 monogenetic cones aged 900–0 ka, defining a complete Na‐alkaline trend Fractionation models show much larger volumes of primitive magmas, indicating the occurrence of an unusually large magma plumbing system A climax of activity occurred during the last glacial maximum (30 ka). Thickness variation of the ice cap may have influenced volcanic activity

Petit‐spot volcanism occurs in intraplate settings along the outer rise of subducting plates. Here we present evidence for petit‐spot type of volcanism from multibeam bathymetry and backscatter data from the Puerto Rico Trench (PRT). It is the first report of such volcanism in the Atlantic basin. Up to 34 possible petit‐spot volcanic cones are mapped in the eastern section of the PRT, with an average diameter of 950 m and a mean height of 92 m. The seamounts are in a region of the PRT that has the longest and highest bending faults, up to 50.6 km long and 1.49 km high. Some of the volcanic cones are associated with fault scarps. The larger bending fault scarps in the region of the volcanic cones suggest the stress state in the eastern PRT is favorable for allowing asthenospheric melt to escape to the surface.

Longgang Volcano (LGV) and Changbaishan Tianchi Volcano (CTV) share a common magmatic source at mantle depths. However, the two volcanoes have produced completely different types of eruptions. By performing 3D inversion of an MT dataset that completely covers the LGV and CTV, we have obtained high-resolution electrical resistivity images. The results reveal that the two volcanoes have distinct magmatic plumbing systems, and this is likely the reason for their different eruptive styles. Results from 3D modeling do not show a magma chamber in the shallow crust beneath LGV, interpreted as the rapid rise of the magma from the mantle is responsible for producing a series of densely distributed volcanic cones in the LGV field. In contrast, there is a magma chamber in the upper crust beneath the CTV, where the fractional crystallization and mixing of magma has occurred. This magma chamber has facilitated multiple centralized eruptions, and thereby has led to the formation of the large CTV volcanic cone. These results indicate that differences in their crustal structures may have controlled the different eruptive activities of the LGV and CTV in CVS, Northeast China.

The Kula Field is the youngest volcanic center in western Türkiye, and consists of various well-preserved volcanic products. Although many geological studies have been conducted in the region, geophysical anomalies have not been studied in detail. Therefore, we analyzed the aeromagnetic anomalies of these volcanic products by performing inversion studies with a recently proposed global optimizer. This study is the first attempt to use success-history-based adaptive differential evolution algorithm (SHADE) for inverting magnetic anomalies. To reduce the computational cost, we introduced the E-SHADE scheme by incorporating an exponential population reduction strategy into the optimizer. A synthetic anomaly study revealed the mathematical nature of the handled inverse problem. Some pre- and post-inversion analyses showed the efficiency of the proposed algorithm. Additionally, we observed that the E-SHADE algorithm produced better results than a commonly used derivative-based local optimizer. Nine profile data sets including magnetic anomalies of some volcanic cones in the Kula region were inverted. It was determined that the basaltic intrusions that allow the mantle material to uplift rapidly are not very deep in the subsurface. Therefore, it is possible that the three-phased volcanism may become active again and generate new alkaline basaltic lava flows in a new phase through these shallow dykes.

The water-saturated phase relations have been determined for a primitive magnesian andesite (57 wt% SiO 2 , 9 wt% MgO) from the Mt. Shasta, CA region over the pressure range 200–800 MPa, temperature range of 915–1,070 °C, and oxygen fugacities varying from the nickel–nickel oxide (NNO) buffer to three log units above NNO (NNO+3). The phase diagram of a primitive basaltic andesite (52 wt% SiO 2 , 10.5 wt% MgO) also from the Mt. Shasta region (Grove et al. in Contrib Miner Petrol 145:515–533; 2003 ) has been supplemented with additional experimental data at 500 MPa. Hydrous phase relations for these compositions allow a comparison of the dramatic effects of dissolved H 2 O on the crystallization sequence. Liquidus mineral phase stability and appearance temperatures vary sensitively in response to variation in pressure and H 2 O content, and this information is used to calibrate magmatic barometers-hygrometers for primitive arc magmas. H 2 O-saturated experiments on both compositions reveal the strong dependence of amphibole stability on the partial pressure of H 2 O. A narrow stability field is identified where olivine and amphibole are coexisting phases in the primitive andesite composition above 500 MPa and at least until 800 MPa, between 975–1,025 °C. With increasing H 2 O pressure ( ), the temperature difference between the liquidus and amphibole appearance decreases, causing a change in chemical composition of the first amphibole to crystallize. An empirical calibration is proposed for an amphibole first appearance barometer-hygrometer that uses Mg# of the amphibole and : This barometer gives a minimum recorded by the first appearance of amphibole in primitive arc basaltic andesite and andesite. We apply this barometer to amphibole antecrysts erupted in mixed andesite and dacite lavas from the Mt. Shasta, CA stratocone. Both high H 2 O pressures (500–900 MPa) and high pre-eruptive magmatic H 2 O contents (10–14 wt% H 2 O) are indicated for the primitive end members of magma mixing that are preserved in the Shasta lavas. We also use these new experimental data to explore and evaluate the empirical hornblende barometer of Larocque and Canil ( 2010 ).

Field investigations and seismic data show that the 16 April 2016 moment magnitude (M ) 7.1 Kumamoto earthquake produced a ~40-kilometer-long surface rupture zone along the northeast-southwest-striking Hinagu-Futagawa strike-slip fault zone and newly identified faults on the western side of Aso caldera, Kyushu Island, Japan. The coseismic surface ruptures cut Aso caldera, including two volcanic cones inside it, but terminate therein. The data show that northeastward propagation of coseismic rupturing terminated in Aso caldera because of the presence of magma beneath the Aso volcanic cluster. The seismogenic faults of the 2016 Kumamoto earthquake may require reassessment of the volcanic hazard in the vicinity of Aso volcano.