scholarly journals The unrest of the San Miguel volcano (El Salvador, Central America): installation of the monitoring network and observed volcano-tectonic ground deformation

2016 ◽  
Vol 16 (8) ◽  
pp. 1755-1769
Author(s):  
Alessandro Bonforte ◽  
Douglas Antonio Hernandez ◽  
Eduardo Gutiérrez ◽  
Louis Handal ◽  
Cecilia Polío ◽  
...  
Keyword(s):  
El Salvador ◽  
Ground Deformation ◽  
Monitoring Network ◽  
Mobile Network ◽  
Density Currents ◽  
Significant Information ◽  
Joint Force ◽  
The North ◽  
Explosive Force ◽  
The Town

Abstract. On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of San Miguel, erupted suddenly with explosive force, forming a column more than 9 km high and projecting ballistic projectiles as far as 3 km away. Pyroclastic density currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force, made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales, was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multiparametric mobile network comprising seismic, geodetic and geochemical sensors (designed to cover all the volcano flanks from the lowest to the highest possible altitudes) and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were colocated into multiparametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

scholarly journals The unrest of S. Miguel volcano (El Salvador, CA): installation of the monitoring network and observed volcano-tectonic ground deformation

2015 ◽  
Vol 3 (10) ◽  
pp. 6117-6148 ◽  
Author(s):  
A. Bonforte ◽  
D. Hernandez ◽  
E. Gutiérrez ◽  
L. Handal ◽  
C. Polío ◽  
...  
Keyword(s):  
El Salvador ◽  
Ground Deformation ◽  
Monitoring Network ◽  
Mobile Network ◽  
Density Currents ◽  
Significant Information ◽  
Joint Force ◽  
The North ◽  
Explosive Force ◽  
The Town

Abstract. On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of S. Miguel, erupted suddenly with explosive force, forming a more than 9 km high column and projecting ballistic projectiles as far as 3 km away. Pyroclastic Density Currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multi-parametric mobile network comprising seismic, geodetic and geochemical sensors, designed to cover all the volcano flanks from the lowest to the highest possible altitudes, and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were co-located into multi-parametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

Multiparametric monitoring of the ongoing eruption of Sangay volcano, Ecuador

2021 ◽  
Author(s):  
Francisco Javier Vasconez ◽  
Silvana Hidalgo ◽  
Stephen Hernández ◽  
Josué Salgado ◽  
Sébastien Valade ◽  
...  
Keyword(s):  
Lava Flow ◽  
Seismic Activity ◽  
Ground Deformation ◽  
Monitoring Network ◽  
Deformation Pattern ◽  
Density Currents ◽  
Eruptive Activity ◽  
Data Set ◽  
Eruptive Style ◽  
Eruptive Episode

<p>During the last two decades, Sangay has been one of the most active Ecuadorian volcanoes. However, because of its remote location and logistically difficult access, monitoring Sangay is a challenging task. The IG-EPN tackled this problem by expanding its terrestrial monitoring network and complementing it with the available satellite data. On 7<sup>th</sup> May 2019, the most recent and ongoing eruptive episode commenced. Compared to the previously monitored and observed eruptive activity at Sangay since the 2000’s, this episode is by far the most intense and the first to affect populated areas due to ash fallouts and numerous lahars. Surface activity is generally characterized by frequent low-to-moderate magnitude ash emissions and a semi-continuous viscous lava flow extrusion. This activity is punctuated by occasional lava flow collapse events, probably associated with pulses of high lava extrusion and that produced long-runout pyroclastic density currents towards the southeastern flank.</p><p>Here, we present the most complete data set of long-term instrumental observations performed at Sangay. SO<sub>2</sub> degassing, seismic activity, ground deformation, ash emissions and thermal anomalies are depicted as a multiparametric sequence to better understand the link between these parameters and the dynamism and eruptive style of this isolated volcano.  </p><p>Correlations between the depicted parameters are not straight-forward, making it hard to identify patterns that might lead to enhanced eruptive activity. High values of SO<sub>2</sub> recorded by the DOAS instruments as well as the TROPOMI satellite sensor seem to coincide with periods of increased eruption rate. Nevertheless, increases in SO<sub>2</sub> flux do not occur systematically before or after these episodes. Seismic activity, characterized by daily counts of individual seismic events, does not demonstrated a clear precursory pattern either. These results indicate that none of the available monitoring parameters currently allow for a timely forecast of the largest and potentially most dangerous eruptions. However, looking at the entire time series we are able to distinguish a slightly but progressive change in the ground deformation displacement associated with a higher number of earthquakes per day prior to the 20 September 2020 paroxysmic event. This eruption produced regional ash fallout which affected significant swaths of farming lands and livestock. Since then, a different ground deformation pattern has taken hold, and coincides with a step decrease in the number of daily earthquakes and a significant increase in the SO<sub>2</sub> mass measured by TROPOMI.</p><p>This behavior matches an open-vent system, where punctual increases in eruptive activity show few precursory signals. The observed increase in all the parameters compared to previous eruptions before 2019 allows us to propose that this eruptive phase is fed by batches of deep and volatile-rich magma which rise to the surface at high ascent rates. The interpretations presented here are an important step towards a better understanding of the dynamism and eruptive style of this very active and isolated volcano. Moreover, the various monitoring parameters from terrestrial to satellite provide a better picture of the behavior of Sangay that could be applied to other remote and open-system volcanoes.</p>

NATO adaptation to current challenges and mechanisms of Ukraine’s cooperation with the North Atlantic Treaty Organization

2019 ◽  
pp. 73-81
Author(s):  
Oleh Poshedin
Keyword(s):  
North Atlantic ◽  
Task Force ◽  
Response Force ◽  
Cyber Attack ◽  
Adaptation Measures ◽  
Joint Force ◽  
Security Environment ◽  
The North ◽  
The North Atlantic ◽  
Area Of Influence

The purpose of the article is to describe the changes NATO undergoing in response to the challenges of our time. Today NATO, as a key element of European and Euro-Atlantic security, is adapting to changes in the modern security environment by increasing its readiness and ability to respond to any threat. Adaptation measures include the components required to ensure that the Alliance can fully address the security challenges it might face. Responsiveness NATO Response Force enhanced by developing force packages that are able to move rapidly and respond to potential challenges and threats. As part of it, was established a Very High Readiness Joint Task Force, a new Allied joint force that deploy within a few days to respond to challenges that arise, particularly at the periphery of NATO’s territory. NATO emphasizes, that cyber defence is part of NATO’s core task of collective defence. A decision as to when a cyber attack would lead to the invocation of Article 5 would be taken by the North Atlantic Council on a case-by-case basis. Cooperation with NATO already contributes to the implementation of national security and defense in state policy. At the same time, taking into account that all decision-making in NATO based on consensus, Ukraine’s membership in the Alliance quite vague perspective. In such circumstances, in Ukraine you often can hear the idea of announcement of a neutral status. It is worth reminding that non-aligned status did not save Ukraine from Russian aggression. Neutral status will not accomplish it either. All talks about neutrality and the impossibility of Ukraine joining NATO are nothing but manipulations, as well as recognition of the Ukrainian territory as Russian Federation area of influence (this country seeks to sabotage the Euro-Atlantic movement of Ukraine). Think about it, Moldova’s Neutrality is enshrined in the country’s Constitution since 1994. However, this did not help Moldova to restore its territorial integrity and to force Russia to withdraw its troops and armaments from Transnistria.

On Riccia marginata and related species (Ricciaceae, Marchantiophyta)

2012 ◽  
Vol 46 ◽  
pp. 298-305 ◽  
Author(s):  
A. D. Potemkin ◽  
T. Ahti
Keyword(s):  
Related Species ◽  
Lake Ladoga ◽  
Leningrad Region ◽  
Sem Images ◽  
North Shore ◽  
The North ◽  
Molecular Studies ◽  
The Future ◽  
The Town

Riccia marginata Lindb. was described by S. O. Lindberg (1877) from the outskirts of the town of Sortavala near the north shore of Lake Ladoga, Republic of Karelia, Russia. The species has been forgotten in most recent liverwort accounts of Europe, including Russia. Lectotypification of R. marginata is provided. R. marginata shares most characters with R. beyrichiana Hampe ex Lehm. It differs from “typical” plants of R. beyrichiana in having smaller spores, with ± distinctly finely areolate to roughly papillose proximal surfaces and a narrower and shorter thallus, as well as in scarcity or absence of marginal hairs. It may represent continental populations of the suboceanic-submediterranean R. beyrichiana, known in Russia from the Leningrad Region and Karelia only. The variability of spore surfaces in R. beyrichiana is discussed and illustrated by SEM images. A comparison with the spores of R. bifurca Hoffm. is provided. The question how distinct R. marginata is from R. beyrichiana needs to be clarified by molecular studies in the future, when adequate material is available. R. marginata is for the time being, provisionally, included in R. beyrichiana.

ANTHROPOGENIC AND ECONOMIC FACTORS OF THE СRIMEAN ECOLOGY

2020 ◽  
pp. 5-14
Author(s):  
N.P. Demchenko ◽  
N.Yu. Polyakova
Keyword(s):  
Business Owners ◽  
Crimean Peninsula ◽  
The North ◽  
Chemical Release ◽  
The Crimea ◽  
Russian Plant ◽  
The Republic ◽  
The Town ◽  
Integrated Indicators ◽  
The Crimean Peninsula

The situation in the ecology of the Crimean Peninsula in recent years was discussed in the article. The analysis of absolute and integrated indicators of the anthropogenic impact showed that the ecological situation remains difficult, and according to some indicators even continues to deteriorate. In summer 2018, the situation had worsened because of the large chemical release of titanium dioxide on the north of the Crimea from the holding pond of a large Russian plant that is situated near the town of Armyansk. This, in turn, led to the contamination of the large territory on the north of the peninsula. This fact indicates insufficient control by officials of the Republic of Crimea over the implementation of the RF laws for environmental protection by business owners of various forms of ownership, especially private ownership, the level of responsibility for the environment of which is very low.

scholarly journals Anatomy of a Paroxysmal Lava Fountain at Etna Volcano: The Case of the 12 March 2021, Episode

2021 ◽  
Vol 13 (15) ◽  
pp. 3052
Author(s):  
Sonia Calvari ◽  
Alessandro Bonaccorso ◽  
Gaetana Ganci
Keyword(s):  
Lava Flow ◽  
Ground Deformation ◽  
Monitoring Network ◽  
Lava Flows ◽  
Etna Volcano ◽  
Lava Fountain ◽  
Eruptive Episode ◽  
Lava Fountains ◽  
Borehole Strainmeter ◽  
Ash Plume

On 13 December 2020, Etna volcano entered a new eruptive phase, giving rise to a number of paroxysmal episodes involving increased Strombolian activity from the summit craters, lava fountains feeding several-km high eruptive columns and ash plumes, as well as lava flows. As of 2 August 2021, 57 such episodes have occurred in 2021, all of them from the New Southeast Crater (NSEC). Each paroxysmal episode lasted a few hours and was sometimes preceded (but more often followed) by lava flow output from the crater rim lasting a few hours. In this paper, we use remote sensing data from the ground and satellite, integrated with ground deformation data recorded by a high precision borehole strainmeter to characterize the 12 March 2021 eruptive episode, which was one of the most powerful (and best recorded) among that occurred since 13 December 2020. We describe the formation and growth of the lava fountains, and the way they feed the eruptive column and the ash plume, using data gathered from the INGV visible and thermal camera monitoring network, compared with satellite images. We show the growth of the lava flow field associated with the explosive phase obtained from a fixed thermal monitoring camera. We estimate the erupted volume of pyroclasts from the heights of the lava fountains measured by the cameras, and the erupted lava flow volume from the satellite-derived radiant heat flux. We compare all erupted volumes (pyroclasts plus lava flows) with the total erupted volume inferred from the volcano deflation recorded by the borehole strainmeter, obtaining a total erupted volume of ~3 × 106 m3 of magma constrained by the strainmeter. This volume comprises ~1.6 × 106 m3 of pyroclasts erupted during the lava fountain and 2.4 × 106 m3 of lava flow, with ~30% of the erupted pyroclasts being remobilized as rootless lava to feed the lava flows. The episode lasted 130 min and resulted in an eruption rate of ~385 m3 s−1 and caused the formation of an ash plume rising from the margins of the lava fountain that rose up to 12.6 km a.s.l. in ~1 h. The maximum elevation of the ash plume was well constrained by an empirical formula that can be used for prompt hazard assessment.

scholarly journals Three-dimensional deformation time series of glacier motion from multiple-aperture DInSAR observation

2019 ◽  
Vol 93 (12) ◽  
pp. 2651-2660 ◽  
Author(s):  
Sergey Samsonov
Keyword(s):  
Time Series ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Three Dimensional ◽  
Data Sets ◽  
Ice Flow ◽  
The North ◽  
Glacier Ice ◽  
Deformation Component ◽  
3D Deformation

AbstractThe previously presented Multidimensional Small Baseline Subset (MSBAS-2D) technique computes two-dimensional (2D), east and vertical, ground deformation time series from two or more ascending and descending Differential Interferometric Synthetic Aperture Radar (DInSAR) data sets by assuming that the contribution of the north deformation component is negligible. DInSAR data sets can be acquired with different temporal and spatial resolutions, viewing geometries and wavelengths. The MSBAS-2D technique has previously been used for mapping deformation due to mining, urban development, carbon sequestration, permafrost aggradation and pingo growth, and volcanic activities. In the case of glacier ice flow, the north deformation component is often too large to be negligible. Historically, the surface-parallel flow (SPF) constraint was used to compute the static three-dimensional (3D) velocity field at various glaciers. A novel MSBAS-3D technique has been developed for computing 3D deformation time series where the SPF constraint is utilized. This technique is used for mapping 3D deformation at the Barnes Ice Cap, Baffin Island, Nunavut, Canada, during January–March 2015, and the MSBAS-2D and MSBAS-3D solutions are compared. The MSBAS-3D technique can be used for studying glacier ice flow at other glaciers and other surface deformation processes with large north deformation component, such as landslides. The software implementation of MSBAS-3D technique can be downloaded from http://insar.ca/.

Inbreeding, Migration and Age at Marriage in Rural Toledo, Spain

1983 ◽  
Vol 15 (1) ◽  
pp. 47-57 ◽  
Author(s):  
R. Calderon
Keyword(s):  
Economic Life ◽  
Neolithic Period ◽  
Ciudad Real ◽  
Age At Marriage ◽  
The North ◽  
Natural Region ◽  
South West ◽  
Different Origins ◽  
The Town ◽  
Common Plant

The natural region of the Jara, with an area of 2500 km2 occupies much of the south west of the province of Toledo, and extends into the provinces of Caceres and Ciudad Real. It is situated between the Tajo and Guadiana rivers, south of the town of Talavera de la Reina, the centre of the economic life in this region. Its highlands are covered with xerophytic vegetation, of which the most common plant is the jara (Cistus ladaniferus), from which this zone takes it name, (Fig. 1). It has been occupied from the neolithic period onwards by peoples of different origins, e.g. Romans, Muslims, Jews, Mozarabs (Jimenez de Gregorio, 1959) but the present population derives from settlement from the north of the Tajo river beginning in the 14th century following the upheavals of the Moslem–Christian wars.

A Carved Stone from D'Arcy, Saskatchewan

1940 ◽  
Vol 5 (4) ◽  
pp. 334-335
Author(s):  
Vladimar Alfred Vigfusson
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Glacial Lake ◽  
Bering Strait ◽  
The North ◽  
Gravel Pit ◽  
North Bank ◽  
The Town

In recent years, the attention of some archaeologists has been directed to the Canadian Northwest with the expectation of finding some evidence or indication of the early migrations of man on this continent. That man reached North America by Bering Strait from Asia, is generally accepted, but the theory that the migrations took place in late Pleistocene times and by way of an open corridor between the Keewatin ice and the Rockies, requires confirmation. It is significant that Folsom and Yuma points from Saskatchewan, described by E. B. Howard, were found mainly in areas bordering the ancient glacial Lake Regina.As a further contribution to this problem, it seems desirable to present a brief description of a carved stone relic found in gravel in central Saskatchewan about three years ago.The stone was found about seven miles southeast of the town of D'Arcy in a gravel pit located on Sec. 9, Tp. 28, Rge. 18, W. 3rd Meridian, on the north bank of a ravine running east into Bad Lake.

The Social Structure of Modern Bamako

Africa ◽  
1965 ◽  
Vol 35 (2) ◽  
pp. 125-142 ◽  
Author(s):  
Claude Meillassoux
Keyword(s):  
Social Structure ◽  
The North ◽  
The Social ◽  
North Bank ◽  
Niger River ◽  
Opening Paragraph ◽  
The Town

Opening ParagraphAccording to a partial census taken in 1960, Bamako city has about 130,000 inhabitants. Small by Western standards, it is still by far the largest city in Mali. At the time of the French conquest Bamako had only between 800 and 1,000 inhabitants; it was the capital of a Bambara chiefdom, grouping about thirty villages on the north bank of the Niger river, with a total of about 5,000 people. The ruling dynasty was that of the Niaré, who, according to their traditions, came from the Kingi eleven generations ago (between 1640 and 1700). For defence against the neighbours and armed slave-raiders fortifications were built around the town and a permanent army of so-fa (horsemen) was raised. Soon after its foundation Bamako attracted Moslem Moors from Twat who settled as marabouts and merchants under the protection of the Niaré's warriors. Among them, the Twati (later to be called Touré) and the Dravé became, alongside and sometimes in competition with the Niaré, the leading families.

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