Emplacement history of a low-viscosity, fountain-fed pantelleritic lava flow

AbstractThe effusion rate of lava is one of the most important eruption parameters, as it is closely related to the migration process of magma underground and on the surface, such as changes in lava flow direction or formation of new effusing vents. Establishment of a continuous and rapid estimation method has been an issue in volcano research as well as disaster prevention planning. For effusive eruptions of low-viscosity lava, we examined the relationship between the nighttime spectral radiance in the 1.6-µm band of the Himawari-8 satellite (R1.6Mx: the pixel value showing the maximum radiance in the heat source area) and the effusion rate using data from the 2017 Nishinoshima activity. Our analysis confirmed that there was a high positive correlation between these two parameters. Based on the linear-regression equation obtained here (Y = 0.47X, where Y is an effusion rate of 106 m3 day−1 and X is an R1.6Mx of 106 W m−2 sr−1 m−1), we can estimate the lava-effusion rate from the observation data of Himawari-8 via a simple calculation. Data from the 2015 Raung activity—an effusive eruption of low-viscosity lava—were arranged along the extension of this regression line, which suggests that the relationship is applicable up to a level of ~ 2 × 106 m3 day−1. We applied this method to the December 2019 Nishinoshima activity and obtained an effusion rate of 0.50 × 106 m3 day−1 for the initial stage. We also calculated the effusion rate for the same period based on a topographic method, and verified that the obtained value, 0.48 × 106 m3 day−1, agreed with the estimation using the Himawari-8 data. Further, for Nishinoshima, we simulated the extent of hazard areas from the initial lava flow and compared cases using the effusion rate obtained here and the value corresponding to the average effusion rate for the 2013–2015 eruptions. The former distribution was close to the actual distribution, while the latter was much smaller. By combining this effusion-rate estimation method with real-time observations by Himawari-8 and lava-flow simulation software, we can build a rapid and precise prediction system for volcano hazard areas.

Download Full-text

Diffusion Timescales of Magmatic Processes in the Moinui Lava Eruption at Mauna Loa, Hawai`i, as Inferred from Bimodal Olivine Populations

Journal of Petrology ◽

10.1093/petrology/egaa058 ◽

2020 ◽

Vol 61 (7) ◽

Cited By ~ 1

Author(s):

F K Couperthwaite ◽

T Thordarson ◽

D J Morgan ◽

J Harvey ◽

M Wilson

Keyword(s):

Lava Flow ◽

Storage Conditions ◽

Magma Storage ◽

Mauna Loa ◽

Low Viscosity ◽

Lava Flow Field ◽

Magmatic Processes ◽

Geochemical Variations ◽

And Storage ◽

Time Information

Abstract The 2·1 ka Moinui lava flow field, erupted from the southwest rift zone of Mauna Loa, Hawai`i, exhibits striking textural and geochemical variations, that can be used to interpret magma processes pre-, syn- and post-eruption. From this lava flow, the duration of magma storage and storage conditions, the timescales over which magma is transported to the surface, and flow emplacement mechanisms at Mauna Loa are determined. Electron microprobe analysis (EMPA) and diffusion chronometry of olivine crystals identify two distinct crystal populations: a primitive, polyhedral olivine population with core compositions of Fo90–88 and a more evolved, platy olivine population with core compositions of Fo83–82. Fe–Mg diffusion modelling of these olivine populations gives distinct timescales for each population; platy olivines yield timescales of days up to a few weeks, while polyhedral olivines yield timescales of months to years. Despite the nature of a well-insulated pāhoehoe flow, meaning that post-emplacement diffusion continues for some time, a wealth of time information can be retrieved concerning pre-eruptive magmatic processes as well as the processes associated with the lava extrusion. The short timescales obtained from the platy olivine crystals and the observed equilibrium between its cores and ambient melt suggest late-stage nucleation and crystal growth in the shallow conduit and during lava emplacement. Conversely, the longer timescales and olivine-melt disequilibrium of the polyhedral olivine crystals suggests accumulation from a deeper source and subsequent transportation to shallow magma storage beneath the summit of Mauna Loa months, or even years before eruption. The chemical and textural details of the Moinui lava reflect the mode of flow emplacement and may have implications for the interpretation of the distribution of spinifex and cumulate olivine within komatiites; high-temperature, low-viscosity lavas, common in the Archean.

Download Full-text

Mount Etna and the 1971 eruption - Lengths of lava flows

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1973.0030 ◽

1973 ◽

Vol 274 (1238) ◽

pp. 107-118 ◽

Cited By ~ 342

Keyword(s):

Lava Flow ◽

High Viscosity ◽

Lava Flows ◽

Mount Etna ◽

High Rate ◽

Low Viscosity ◽

Depression Measurement ◽

Lateral Extent ◽

The One ◽

Single Flow

The principal factor influencing the length of a lava flow is the rate of effusion. With a high rate the lava flows rapidly from the source and tends to form an extensive and far-reaching flow which is simple in character (i.e. made of a single flow unit). With a low rate the lava tends to pile up layer upon layer to form a local accumulation of limited lateral extent near the source, and this accumulation is strongly compound in character (i.e. divisible into flow units). The initial viscosity affects the length indirectly by controlling the thickness of the extrusion, and this thickness control is capable of accounting for the fact that the median length of low-viscosity basaltic extrusions is 3.2 times that of high-viscosity andesite, trachyte and rhyolite ones. Other factors, such as the local topography, are thought to be relatively unimportant, an exception being when lava is ponded in a topographic depression. Measurement of the rate of effusion may be critical in any attempt to predict the distance that a lava flow will travel, such as the one which threatened Fornazzo and other towns and villages on Etna in 1971.

Download Full-text

Volcanology and inflation structures of an extensive basaltic lava flow in the Payenia Volcanic Province, extra-Andean back arc of Argentina

Andean geology ◽

10.5027/andgeov46n2-3180 ◽

2019 ◽

Vol 46 (2) ◽

pp. 279 ◽

Cited By ~ 1

Author(s):

Mauro Ignacio Bernardi ◽

Gustavo Walter Bertotto ◽

Alexis Daniel Ponce ◽

Yuji Orihashi ◽

Hirochika Sumino

Keyword(s):

Lava Flow ◽

Liquid Core ◽

Internal Flow ◽

Middle Pleistocene ◽

High Concentration ◽

Volcanic Province ◽

Low Viscosity ◽

Effusion Rates ◽

Flow Pathways ◽

P Type

The El Puesto lava flow is located in the Payenia Volcanic Province (central-western Argentina), has a length of 70 km and is Middle Pleistocene in age (0.200±0.027 Ma). The flow shows a P-type pahoehoe structure and exhibits several inflation structures, mainly tumuli and also inflation ridges and lava rises. Lava rise pits and radial or annular clefts are common features associated with inflation structures. The gentle slope on which the flow moved (≈0.5°) allowed the lateral coalescence of lobes at the flow front and the development of an external rigid crust that insulated the liquid core. Lava tunnels are frequent and the lava tunnel named “Cueva de Halada” which is located at its medium portion is the best example of a drainage master tube which formed from the cooling of the crust around a stable inflated flow. Tumuli alignments and long inflation ridges reveal the existence of larger tunnels within the flow. Inflation structures may occur in high concentration belts that converge on a single main belt which is assigned to an anastomosed network of internal flow pathways within the main lava body. The development of inflation structures and lava tunnels require low to moderate effusion rates. An average lava supply rate of 1.8x10-4 m3/s and an inflation time of about 15 days were estimated for an average tumulus of this flow. A high and sustained supply of low viscosity lava (η’=1550 - 483 Pa s) was inferred that initially generated a sheet flow of great areal extension. The reduction in effusion rates could then allowed the development of tunnels that carried lava to the distal fronts, generating localized inflation phenomena throughout the lava flow.

Download Full-text

Eruptive and tectonic history of the Endeavour Segment, Juan de Fuca Ridge, based on AUV mapping data and lava flow ages

Geochemistry Geophysics Geosystems ◽

10.1002/2014gc005415 ◽

2014 ◽

Vol 15 (8) ◽

pp. 3364-3391 ◽

Cited By ~ 26

Author(s):

David. A. Clague ◽

Brian M. Dreyer ◽

Jennifer B. Paduan ◽

Julie F. Martin ◽

David W. Caress ◽

...

Keyword(s):

Lava Flow ◽

Juan De Fuca Ridge ◽

Mapping Data ◽

Fuca Ridge ◽

Tectonic History ◽

Juan De Fuca ◽

History Of ◽

Endeavour Segment

Download Full-text

Recent eruption history inferred from eruption ages of the two latest lava flows using multi-dating at Yokodake Volcano, Japan

Earth Planets and Space ◽

10.1186/s40623-020-01220-3 ◽

2020 ◽

Vol 72 (1) ◽

Cited By ~ 1

Author(s):

Hiroya Nitta ◽

Takeshi Saito ◽

Yorinao Shitaoka

Keyword(s):

Lava Flow ◽

Volcanic Activity ◽

Active Volcano ◽

Lava Flows ◽

Eruption Rate ◽

Dating Methods ◽

Paleomagnetic Dating ◽

History Of ◽

Eruption History ◽

Recent Eruption

Abstract Reconstruction of the eruption history of an active volcano is necessary to elucidate its volcanic activity and to assess the probability of its volcanic eruption. Yokodake volcano in central Japan is the only active volcano among the Yatsugatake volcano group. It has effused nine lava flows, most of which have not been dated. For this study, we ascertained the eruption ages of the latest lava (Y9) and second most recent lava (Y8) using radiocarbon (14C), thermoluminescence (TL), and paleomagnetic dating methods. Results revealed the eruption ages of the two lava flows and the recent eruption history of Yokodake volcano. Yokodake volcano effused its Y8 lava flow at ca. 3.4 ka, ejected NYk-2 tephra with explosive eruption at ca. 2.4–2.2 ka, and effused the Y9 lava flow associated with Y9-T tephra at ca. 0.6 ka. Magma eruption rates of Yokodake at 34 ky and 3.4 ky were estimated as about 9 × 10−3 km3/ky and 1 × 10−2 km3/ky, indicating a stable eruption rate maintained during the past 34 ky. This result suggests that Yokodake volcano retains some potential for eruption, although the volcanic activity of the Yatsugatake volcanoes (10−1–10−2 km3/ky) has weakened over time.

Download Full-text

Tube-fed pahoehoe lava-flow features of Azorella Peninsula, Heard Island, southern Indian Ocean

Polar Record ◽

10.1017/s0032247400025699 ◽

1998 ◽

Vol 34 (190) ◽

pp. 225-236 ◽

Cited By ~ 2

Author(s):

Kevin Kiernan ◽

Anne McConnell ◽

Tony Yates

Keyword(s):

Indian Ocean ◽

Lava Flow ◽

High Temperatures ◽

Southern Indian Ocean ◽

Lava Tubes ◽

Low Viscosity ◽

Heard Island ◽

Flow Features ◽

Scoria Cones ◽

Topographic Relief

AbstractAzorella Peninsula on Heard Island in the sub-Antarctic comprises basaltic scoria that is overlain by basalt flows. Typical tube-fed pahoehoe flows characteristic of some Hawaiian-type volcanoes occur. The volcanic landforms of the peninsula include highly degraded volcano remnants and undissected scoria cones, pahoehoe flows, lava rises, tumuli, open vertical volcanic conduits, and lava tubes. Features produced by lava inflation are widespread but are generally of low topographic relief. Many detailed lava-flow features are preserved in dramatically fresh condition within the protected environment of lava tubes. They highlight the efficacy of the lava tubes in maintaining high temperatures and low viscosity of the flowing lava. The lava tubes on Heard Island are the only features of their kind hitherto recorded from Antarctic and sub-Antarctic latitudes.

Download Full-text

Morphological types in the Deccan Volcanic Province, India: implications on emplacement dynamics of continental flood basalts

Geological Society London Special Publications ◽

10.1144/sp518-2020-246 ◽

2021 ◽

pp. SP518-2020-246

Author(s):

Vivek S. Kale ◽

Gauri Dole ◽

Shilpa Patil Pillai ◽

Poushali Chatterjee ◽

Makarand Bodas

Keyword(s):

Lava Flow ◽

Flood Basalt ◽

Deccan Volcanic Province ◽

Flood Basalts ◽

Volcanic Province ◽

Continental Flood Basalts ◽

Substrate Topography ◽

History Of ◽

Multiple Pulses ◽

Stacking Patterns

AbstractWe review and compare morphologies from continental basaltic lavas, using examples from the Deccan Volcanic Province to compile their internal configurations, mutual associations and compare them. The mechanism of endogenous transfer of lava within an insulating (rapidly developed) crust provides an efficient mode of dispersal of the molten lava in flood basalts. The growth of the lava flow can be achieved by a single extrusion or by multiple pulses of endogenous emplacement that enable the lava to efficiently spread over large areas and thicken.We show that the morphology of a lobe manifests the response of the molten lava to several parameters (including volumetric rate of emplacement, substrate topography, viscosity, vapour loss, etc) that govern the dynamics and cooling history of basaltic lava after it starts to spread on the surface. The lateral transition from one morphology to another within lobes of a lava flow is a testimony to the interactive response of the lava dynamics and rheology to variation in the local systems in which they were emplaced. The morphologies do not evolve as rigid partitioned categories from ‘áā and pāhoehoe lava types’ but as parametric progression of interactive variations in the spreading and cooling lava.A hierarchical recognition of lobes, flows and flow fields and mapping of the morphology (and their lateral transition or continuity) combined with the stacking patterns provides the volcanological framework for a sound stratigraphic mapping of flood basalts. Such an architectural documentation of flood basalt provinces will lead to robust models of their eruptive histories.

Download Full-text