scholarly journals Sound Waves Help Scientists Track Volcanic Eruptions

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
JoAnna Wendel
Keyword(s):  
Volcanic Activity ◽  
Seismic Waves ◽  
Volcanic Eruptions ◽  
Sound Waves

When sound waves hit the ground, they shake seismometers like earthquake waves. Scientists can now use these sound-induced seismic waves to investigate volcanic activity.

scholarly journals Near-real-time volcanic cloud monitoring: insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
S. Engwell ◽  
L. Mastin ◽  
A. Tupper ◽  
J. Kibler ◽  
P. Acethorp ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Activity ◽  
Volcanic Ash ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
Process Data ◽  
Cloud Monitoring ◽  
Satellite Sensors ◽  
Volcanic Cloud

AbstractUnderstanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

scholarly journals Volcanic activity sparks the Arctic Oscillation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weizheng Qu ◽  
Fei Huang ◽  
Jinping Zhao ◽  
Ling Du ◽  
Yong Cao
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruption ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Volcanic Eruptions ◽  
The Arctic ◽  
Vortex System ◽  
Significant Fluctuation ◽  
The Arctic Oscillation

AbstractThe parasol effect of volcanic dust and aerosol caused by volcanic eruption results in the deepening and strengthening of the Arctic vortex system, thus stimulating or strengthening the Arctic Oscillation (AO). Three of the strongest AOs in more than a century have been linked to volcanic eruptions. Every significant fluctuation of the AO index (AOI = ΔH_middle latitudes − ΔH_Arctic) for many years has been associated with a volcanic eruption. Volcanic activity occurring at different locations in the Arctic vortex circulation will exert different effects on the polar vortex.

scholarly journals Increment in the volcanic unrest and number of eruptions after the 2012 large earthquakes sequence in Central America

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gino González ◽  
Eisuke Fujita ◽  
Bunichiro Shibazaki ◽  
Takumi Hayashida ◽  
Giovanni Chiodini ◽  
...  
Keyword(s):  
Central America ◽  
Seismic Waves ◽  
Dynamic Stress ◽  
Reaction Times ◽  
Volcanic Eruptions ◽  
Large Magnitude ◽  
Tectonic Earthquakes ◽  
The Impact ◽  
The Relationship ◽  
Large Earthquakes

AbstractUnderstanding the relationship cause/effect between tectonic earthquakes and volcanic eruptions is a striking topic in Earth Sciences. Volcanoes erupt with variable reaction times as a consequence of the impact of seismic waves (i.e. dynamic stress) and changes in the stress field (i.e. static stress). In 2012, three large (Mw ≥ 7.3) subduction earthquakes struck Central America within a period of 10 weeks; subsequently, some volcanoes in the region erupted a few days after, while others took months or even years to erupt. Here, we show that these three earthquakes contributed to the increase in the number of volcanic eruptions during the 7 years that followed these seismic events. We found that only those volcanoes that were already in a critical state of unrest eventually erupted, which indicates that the earthquakes only prompted the eruptions. Therefore, we recommend the permanent monitoring of active volcanoes to reveal which are more susceptible to culminate into eruption in the aftermath of the next large-magnitude earthquake hits a region.

SedCas_Volcano: Simulating decadal patterns of lahar hazard and sediment transfer following volcanic disturbance in the Belham River Valley, Montserrat 

2021 ◽  
Author(s):  
James Christie ◽  
Georgina Bennett ◽  
Jacob Hirschberg ◽  
Jenni Barclay ◽  
Richard Herd
Keyword(s):  
Volcanic Activity ◽  
Vegetation Cover ◽  
Volcanic Eruptions ◽  
River Valley ◽  
Sediment Supply ◽  
Recovery Cycle ◽  
Frequency Distributions ◽  
Volcanic Disturbance ◽  
Multi Phase ◽  
Disturbance Recovery

<p>Explosive volcanic eruptions are among the most significant natural disturbances to landscapes on Earth. The widespread and rapid influx of pyroclastic sediment, together with subsequent changes to topography and vegetation cover, drives markedly heightened runoff responses to rainfall and increased downstream water and sediment fluxes; principally by way of hazardous lahars. The nature and probability of lahar occurrence under given rainfall conditions evolves as the landscape responds and subsequently recovers following the disturbance. The relationship between varying sediment supply, rainfall patterns, vegetation cover and lahar activity is complex, and impedes forecasting efforts made in the interest of hazard and land use management. Thus, developing an improved understanding of how these systems evolve in response to volcanic eruptions is of high importance.</p><p>Here we present SedCas_Volcano[MOU1] , a conceptual sediment cascade model, designed to simulate the first-order trends, such as magnitude-frequency distributions or seasonal patterns, in lahar activity and sediment transport. We use the Belham River Valley, Montserrat, as a case study. This small (~15km<sup>2</sup>) catchment has been repeatedly disturbed by five phases of volcanic activity at the Soufrière Hills Volcano since 1995. The multi-phase nature of this eruption, together with the varying nature and magnitude of disturbances throughout the eruption, has driven a complex disturbance-recovery cycle, which is further compounded by inter-annual climatic variations (e.g. ENSO). Lahars have occurred frequently in response to rainfall in the Belham River Valley, and their occurrence has evolved through the repeated disturbance-recovery cycle. This activity has resulted in significant net valley floor aggradation and widening, consequent burial and destruction of buildings and infrastructure, as well as coastal aggradation of up to ~250m. Within SedCas_Volcano, we account for evolving sediment supply, vegetation cover and rainfall, to simulate the lahar activity and channel change observed in the Belham River Valley since January 2001. Following this, we test the model under different hypothetical eruptive scenarios. [MOU2] Our goal is to assess the efficacy of such models for reproducing patterns of lahar activity and geomorphic change in river systems that are repeatedly disturbed by volcanic activity.</p>

scholarly journals Simulation of Historic Glacier Variations with a Simple Climate-Glacier Model

1988 ◽  
Vol 34 (118) ◽  
pp. 333-341 ◽  
Author(s):  
Johannes Oerlemans
Keyword(s):  
Volcanic Activity ◽  
Climate Model ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Solar Variability ◽  
Surface Radiation ◽  
Greenhouse Warming ◽  
Radiation Balance ◽  
Equilibrium Line Altitude ◽  
Modelling Studies

AbstractGlacier variations during the last few centuries have shown a marked coherence over the globe. Characteristic features are the maximum stand somewhere in the middle of the nineteenth century, and the steady retreat afterwards (with some minor interruptions depending on the particular region). In many papers, qualitative statements have been made about the causes of these fluctuations. Lower temperatures associated with solar variability and/or volcanic activity are the most popular explanations. In particular, the statistical relation between glacier activity and major volcanic eruptions appears to be strong.In this paper, an attempt is made to simulate recent glacier fluctations with a physics-based model. A simple climate model, calculating perturbations of surface-radiation balance and air temperature (not necessarily in phase!), is coupled to a schematic time-dependent glacier model. The climate model is forced by volcanic activity (Greenland acidity and/or Lamb’s dust-veil index) and greenhouse warming. Solar variability was not considered, because its effect on climate has still not been demonstrated in a convincing way. The output is translated into variations in equilibrium-line altitude, driving the glacier model.The simulated variations in glacier length show good agreement with the observed record, but the amplitude is too small. This is improved when mass-balance gradients are assumed to be larger in warmer climates. Compared to recently published modelling studies of particular glaciers, in which series of local parameters (e.g. tree-ring width and temperature) were used as forcing, the present simulation is better. This suggests that the radiation balance is a decisive factor with regard to glacier variations on longer time-scales. The model experiments lend support to the results of Porter (1986), who concluded from a more qualitative study that a strong relation exists between periods of increased volcanic activity and glacier advances.A comparison of some selected runs shows that, according to the present model, the greenhouse warming would be responsible for about 50% of the glacier retreat observed over the last 100 years.

A continuous 250-year record of volcanic activity from Princess Elizabeth Land, East Antarctica

2002 ◽  
Vol 14 (1) ◽  
pp. 55-60 ◽  
Author(s):  
M.J. Zhang ◽  
Z.Q. Li ◽  
C.D. Xiao ◽  
D.H. Qin ◽  
H.A. Yang ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Major Ions ◽  
Accumulation Rate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
East Antarctica ◽  
Mean Annual Temperature ◽  
High Definition ◽  
Concentration Data ◽  
High Accumulation

A 51.85 m ice core collected from site LGB65 (accumulation rate 127 kg m−2 a−1, mean annual temperature −33.1°C) in Princess Elizabeth Land, East Antarctica, during the 1996–97 Chinese First Antarctic Inland Expedition has been analysed for chemical composition and oxygen isotope ratio. Based on the high definition of seasonal variations of major ions, the ice core was dated with errors within ± 3 years. The continuous sulphate analysis of the ice core provides an annually resolved proxy history of southern hemisphere volcanism in the past 250 years. High nssSO42−, concentrations seem to be well correlated to some explosive volcanic eruptions, such as Tambora (AD 1815), Coseguina (AD 1835), Krakatoa (AD 1883) and Tarawera (AD 1886). In comparison with other volcanic records, it seems that nssSO42− concentration data provide a better proxy for detecting volcanic activity than nssSO42− fluxes in low and intermediate accumulation regions, however, in high accumulation regions, small and moderate events may be more identifiable using of nssSO42− flux data.

scholarly journals On the agency of water in volcanic eruptions; with some observations on the thickness of the Earth's crust from a geological point of view; and on the primary cause of volcanic action

1887 ◽  
Vol 41 (246-250) ◽  
pp. 117-173 ◽  
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Point Of View ◽  
Earth’S Crust ◽  
Difference Of Opinion ◽  
Established Fact ◽  
The Subject ◽  
Earth's Crust

The important part played by water in volcanic eruptions is a well recognised and established fact, but there is great difference of opinion among geologists as to whether water should be considered the primary or secondary agent, and as to the mode, time, and place of its intervention. The prevailing opinion in this country is that water is the primary cause of volcanic activity. Whichever view may be adopted, the subject is one which is so largely concerned with the laws regulating the underground circulation of water, that the consideration of the two questions must proceed pari passu .

scholarly journals Mapping Recent Fluctuations of Shoestring Glacier, Mount St. Helens (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 203
Author(s):  
Melinda M. Brugman
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Aerial Photographs ◽  
Mass Balances ◽  
Mountain Glacier ◽  
Local Climate ◽  
Surficial Geology ◽  
Glacier Fluctuations ◽  
Glacier Terminus ◽  
Mount St Helens

The terminus position of Shoestring Glacier, Mount St. Helens, has pulsated over the last few centuries, generally following local climate trends, but the pattern of advance and retreat has been strongly modulated by effects of local volcanic activity. In this paper, I discuss the techniques employed to map and survey fluctuations in ice velocity, thickness, and terminus position of Shoestring Glacier. Solutions to major problems in acquiring and interpreting data peculiar to an active volcano are also explained. Results show that this steep mountain glacier responds quickly and dramatically to local environmental changes. The effects of volcanic activity are distinguished from internal instabilities and local climate change by combining information obtained using a variety of techniques, including field surveying, contour-mapping using stereo-aerial photographs, photo-documentation, and published historical accounts, In this paper I will focus attention on surveying and mapping conducted since 1979 at Shoestring Glacier, but will also discuss methods used to identify historic and “prehistoric” glacier fluctuations back to the early 1800s. The field survey was conducted at the glacier from mid-1979 to late 1983, during several eruptive episodes, major earthquakes, and covering winter and summer velocity and thickness changes. (Brugman and Post, 1980; Brugman and Meier, 1981). Coordinates of glacier velocity markers and the survey reference net were monitored with several different theodolites and electronic distance meters. In addition, topographic maps of Shoestring Glacier and vicinity were made for the years between 1979 and 1982, for the purpose of characterizing the drastic changes which occurred during the volcanic eruption of Mount St. Helens of May 18, 1980. The maps were constructed with 2 m contour intervals, using three sets of vertical aerial photographs. The difference between maps results in two plots showing the surficial changes caused by the volcanic field-checked against ground survey data on thickness change, using standard techniques. Overall, this study included monitoring glacier flow, configuration, and thickness changes at Shoestring Glacier since mid-1979, and also monitoring any changes in the local survey net due to ground deformation associated with nearby volcanic activity. In addition, photographic and written documentation of recent glacier fluctuations at Mount St. Helens was compiled from a variety of sources, which included local explorers, scientists, mountaineers, aviators, and historians. From this information, I was able to obtain the general pattern of Shoestring Glacier terminus fluctuations since the early 1900s. To extend the study further back in time, I also mapped the local surficial geology surrounding Shoestring Glacier using aerial photographs and ground studies. Because Mount St. Helens is a highly active, young volcano, a major problem was to distinguish glacier moraines, built during a recent ice advance, from volcanic levees built during passage of a recent lahar. Both lahar levees and glacier moraines exist along the glacier margin and most have been dissected and scoured by later mudflows. This study required the separate identification of glacial lag-till, from mudflow and rock avalanche debris. Comparison of depositional and erosional features generated by the several major lahars which decended over the Shoestring Glacier during the 1980 eruptions to pre-1980 surficial geology shows that glacier and lahar deposits are closely intermingled, but they can be distinguished on the basis of surface morphology obtained from aerial photographs, supported by field mapping of sedimentary structures. The dominant pre-1980 surficial deposits were laid down during a time of intense volcanism dating from 1800-1857, when the Shoestring Glacier was initially at its most advanced terminus position in its limited geologic record. During the early 1900s, several minor historic eruptions deposited ash and debris as distinctive englacial debris layers, which were well preserved within the glaciers on Mount St. Helens. Rock material deposited in the early to mid-1800s from glacier advances and volcanic eruptions can be distinguished from volcanic material deposited during the early 1900s because of the minor effect these later eruptions had on the glaciers of Mount St. Helens. This study shows that, over the last few centuries, repeated eruptions of Mount St. Helens have caused important changes in the mass balance of Shoestring Glacier. During several volcanic eruptions since 1800, the Shoestring and nearby glaciers have been deeply blanketed with rock ejecta and avalanche and mudflow debris, which could have increased the glacier mass balances. In contrast, the dominant effect of major volcanic eruptions on the Shoestring Glacier has led to strongly negative mass balances due to scouring, melting, and blasting away of glacier snow and ice. Deep incision of the glacier and its surrounding topography is clearly evident from the maps produced during this study, both during and before 1980. This melting and scouring occurred as pyroclastic flows and lahars swept down the glacier-filled canyon from the summit of the volcano and has probably occurred repeatedly since the canyon holding the Shoestring Glacier was first cut, approximately two thousand years ago. The eruption of Mount St. Helens on May 18, 1980, when the Shoestring Glacier was beheaded, deeply incised, and covered by volcanic ejecta and mudflow debris, is the most recent example of the highly variable environment in which the glacier continues to survive.

The Linkage of the Different Distinct Great Volcanic Eruptions of the Thera (Santorini) in the Range (1700÷1450 ±14) BC and the Related Subsequent Intensifications of the Global Seismicity and Volcanic Activity in the End of the 19TH Century and

2014 ◽  
Vol 4 (2) ◽  
pp. 484-516 ◽  
Author(s):  
Sergey V. Simonenko
Keyword(s):  
20Th Century ◽  
Volcanic Activity ◽  
Gravitational Interaction ◽  
Volcanic Eruptions ◽  
The Sun ◽  
Differential Formulation ◽  
The Earth ◽  
Stationary Energy ◽  
Global Seismicity ◽  
In The Beginning

The article presents the development of the cosmic geophysics (representing the deterministic thermohydrogravidynamic theory based on the author’s generalized differential formulation of the first law of thermodynamics)  by taking into account the non-stationary energy gravitational influences on the Earth of the Sun (owing to the gravitational interaction of the Sun with the outer large planets) along with the non-stationary energy gravitational influences of the system Sun-Moon, the Venus, the Mars and the Jupiter.  The author presents the evidence of the founded ranges of the fundamental global seismotectonic,  volcanic and climatic periodicities () years and  () years (determined by the combined predominant non-stationary energy gravitational influences on the Earth of the system Sun-Moon, the Venus, the Mars,  the Jupiter and the Sun owing to the gravitational interactions of the Sun with the Jupiter and the Saturn) based on the established links between the different distinct great eruptions of the Thera (Santorini) in the range (1700÷1450 ±14) BC and the subsequent intensifications of the global seismicity and volcanic activity in the end of the 19th  century and in the beginning of the 20th century, in the end of the 20th century, and in the beginning of the 21st century AD.

The magneto-seismic method in geoscience

2021 ◽  
Vol 40 (3) ◽  
pp. 194-201
Author(s):  
Qiuzi Li ◽  
Harry W. Deckman ◽  
Deniz Ertaş ◽  
Lang Feng
Keyword(s):  
Magnetic Field ◽  
Seismic Response ◽  
Seismic Waves ◽  
Signal To Noise Ratio ◽  
Cross Product ◽  
Seismic Effect ◽  
Sound Waves ◽  
Current Dipole ◽  
Potential Applications ◽  
The Difference

Key concepts and potential applications associated with a phenomenon hitherto unexplored by the geoscience community, which we have named the magneto-seismic effect, are introduced. The method is based on the simple principle that when an electric charge moves in the presence of an external magnetic field, the charge carrier experiences an instantaneous force, which is equal to the vector cross product of the current it carries and the magnetic field that is present. This “Lorentz force” can create both compressional and shear sound waves in electrical conductors by passing an alternating current through them via an electromagnetic source. In laboratory settings, this magneto-seismic effect can produce readily detectable rock frame displacements. This opens up the possibility of developing new experimental methods to interrogate elastic and poroelastic response of rocks in a broad frequency range from subhertz to megahertz, potentially closing the frequency gap between traditional ultrasonic characterization and properties of interest in the seismic frequency band. In exploration settings, electric current dipole/bipole sources, or novel rotating magnetic dipole sources, can be used to generate electric currents at depth. These currents produce seismic waves at interfaces (or boundaries) where conductivity abruptly changes. The amplitude and propagation directions of these generated seismic waves depend on the relative orientation of the interfaces (or boundaries) with respect to the earth's magnetic field. These seismic waves can then be recorded by receivers at the surface and, in principle, might be processed to yield a resistivity map with seismic resolution. It is shown that processing to obtain a signal from deep targets is significantly limited by seismic background noise. However, an acceptable signal-to-noise ratio might be achieved for shallower targets. The difference between the magneto-seismic response and the previously well-studied electro-seismic response will be discussed.

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