Filtering by Subject: Volcanology
Published: 2019-08-07
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Host rock deformation in active volcanic settings can signal and be used to constrain magma emplacement. Yet it is difficult to evaluate the accuracy of intrusion parameters derived from inversion of deformation signals because we cannot test estimates by directly accessing the magma body. Physical modelling is thus critical to understanding how intrusion translates into host rock deformation, [...]
Published: 2019-07-09
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Fogo volcano belongs to the Cape Verde hotspot and its most recent eruption occurred from November 2014 to February 2015. From January to December 2016 we operated a temporary seismic network on Fogo and were able to locate 289 earthquakes in total. While most of the events occur at distances > 25 km near the neighboring island of Brava. However, on 15th August 2016 we recorded an isolated [...]
Published: 2019-07-08
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Acidic lava domes are a special monogenetic volcano type with explosive eruption hazards. Such domes raise questions about the nature of monogenetic volcanism. We study the iconic Puy de Dôme (Chaîne des Puys, Auvergne) that gave its name to dome landforms. It is asymmetric with one side more rugged and steeper than the other. Using mapping and paleomagnetism we find that it was tilted by ~20° [...]
Published: 2019-07-05
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Saucer-shaped sills are common in sedimentary basins worldwide. The saucer shape relates to asymmetric stress distributions at the sill-tip during intrusion caused by bending of the overburden. Most saucer-shaped sill models are conducted without tectonic stress. Model results are poorly correlated with natural sills in that: (1) modelled saucers are much steeper than natural sills; and (2) [...]
Published: 2019-07-05
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Igneous sills are common features in tectonically active regions, acting as nascent magma storage systems, or feeding eruptions at large lateral distances from the magma source. Sills reaching a critical radius, rc, relative to their initial depth, H, interact with Earth’s surface, leading to mild discordant growth at angle [theta] typically <10[deg] forming saucer-shaped sills; commonly [...]
Published: 2019-07-04
Subjects: Earth Sciences, Fluid Dynamics, Geology, Physical Sciences and Mathematics, Physics, Sedimentology, Volcanology
Pyroclastic density currents are a life-threatening volcanic hazard. Our understanding and hazard assessments of these flows primarily rely on interpretations of their deposits. The occurrence of stratified layers, cross-stratification, and dune bedforms in these deposits has been assumed as indicative of dilute, turbulent, flows causing traction-dominated deposition. Here we show, through [...]
Published: 2019-06-28
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Eruptive activity shapes volcanic edifices. The formation of broad caldera depressions is often associated with major collapse events, emplacing conspicuous pyroclastic deposits. However, caldera subsidence may also proceed silently by magma withdrawal at depth, more difficult to detect. Ambrym, a basaltic volcanic island, hosts a 12-km wide caldera and several intensely-degassing lava lakes [...]
Published: 2019-06-20
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Volcanology
Reconstructions of volcanic aerosol radiative forcing are required to understand past climate variability. Currently, reconstructions of pre-20th century volcanic forcing are derived from sulfate concentrations measured in polar ice cores, predominantly using a relationship between average ice sheet sulfate deposition and stratospheric sulfate aerosol based on a single explosive eruption - the [...]
Published: 2019-06-07
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
The chemistry of gases measured in ice caves and from warm geothermal ground at Erebus volcano, Antarctica, show that gas emissions are dominated by air, with varying amounts of added volcanic CO2. This suggests widespread circulation of air through the volcanic edifice, as well as spatially or temporally varying contributions from magmatic degassing. The resulting gases are further modified by [...]
Published: 2019-06-03
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Dike intrusions are often associated with surface deformation and propagating swarms of earthquakes. These are understood to be manifestations of the same underlying physical process, although rarely modeled as such. We construct a physics-based model of the 2014 B\ar{\dh}arbunga dike, by far the best observed large dike ($> 0.5$ km$^3$) to date. We constrain the background stress state [...]
Published: 2019-05-06
Subjects: Earth Sciences, Geochemistry, Geology, Mineral Physics, Physical Sciences and Mathematics, Volcanology
Distorted olivines of enigmatic origin are ubiquitous in erupted products from a wide range of volcanic systems (e.g., Hawaiʻi, Iceland, Andes). Investigation of these features at Kīlauea Volcano, Hawai’i, using an integrative crystallographic and chemical approach places quantitative constraints on mush pile thicknesses. Electron back-scatter diffraction (EBSD) reveals that the microstructural [...]
Published: 2019-04-17
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Buried volcanoes are increasingly identified in the sedimentary basins both on lands and continental margins. However, their roles on the post-eruption fluid flows are still poorly understood, which greatly influence the estimate of seal integrity and increase the hydrocarbon exploration/production risks. Here we use high-resolution 3D seismic reflection and borehole data from the northern South [...]
Published: 2019-02-28
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
On May 10th, 2018, an unprecedented long and intense seismic crisis started offshore, east of Mayotte, the easternmost of the Comoros volcanic islands. The population felt hundreds of events. Over the course of one year, 32 earthquakes with magnitude greater than 5 occurred, including the largest event ever recorded in the Comoros (Mw = 5.9 on May 15th, 2018). Earthquakes are clustered in space [...]
Published: 2019-02-15
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Volcanogenic tsunamis are one of the deadliest volcanic phenomena. Understanding their triggering processes and mitigating their effect remains a major challenge. On 22 December 2018, flank failure of the Anak Krakatau volcano in Indonesia generated a tsunami which killed more than 400 people. This event was captured in unprecedented detail by high-resolution satellite imagery and eyewitness [...]
Published: 2019-02-11
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
We appreciate the opportunity to respond to Hogg et al.’s critique of HDK182. We consider that neither the arguments nor the additional data presented by Hogg et al. provides a basis for rejecting our hypothesis of magmatic carbon bias in proximal 14C ages for the Taupo eruption. Hogg et al. focus on the wiggle match and Kaipo Bog dates out of > 40 data points, whereas our paper focused on the [...]