I.—A Remarkable Rock Stream in East Iceland

1917 ◽  
Vol 4 (3) ◽  
pp. 97-102 ◽  
Author(s):  
Leonard Hawkes
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Compact Mass ◽  
Peculiar Character ◽  
Unusual Type

In his account of the volcanoes of Iceland, Thoroddsen describes two types of acid lavas which have been extruded in post-Glacial, prehistoric times. First are the lavas of the Torfajökull district, of the usual nature of acid flows, building up a compact mass of bluish-grey rock with an outer casing of obsidian and pumice. These lavas have been poured out in the post-Tertiary country, but the second type of stream is found most frequently in the older parts of the island, which otherwise have witnessed no volcanic eruptions since Tertiary times. This type of flow results from eruptions of a peculiar character in which “vast outflows of halfmelted and unmelted masses of liparite, poured out from cauldronshaped depressions, stretch down into the lowlands” (1, p. 503). The best example of these “Liparitische Bloekströme” occurs in the Lodmundarfjord district, E. Iceland, and is especially described by Thoroddsen (2, pp. 159–161). In this paper the contention is put forward that the Lodmundarfjord blockstream is not a lava-flow but an unusual type of glacial moraine.

scholarly journals Decadal Modeling (2004-2021) Ecosystem Recovery Impacted by Mount Semeru Eruption Volcanic Activities using Vegetation Succession as a Proxy in the Lava Flow Stream

2021 ◽  
Author(s):  
Andri Wibowo
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Natural Process ◽  
Vegetation Succession ◽  
Tree Line ◽  
Ecosystem Recovery ◽  
Barren Land ◽  
Succession Rate ◽  
Fertile Ground ◽  
Ecosystem Transformation

Volcano eruptions undoubtly cause environmental impacts and damages. After the eruption, there will be vast barren land that was previously fertile ground covered by vegetation and tree line. Lava from an eruption will flow to the land via a river stream, destroying everything in its path, including vegetation. While the ecosystem actually has an ability to recover. The natural process of ecosystem recovery is related to the succession of vegetation. Then this study aims to assess and model how the ecosystem can recover and how the vegetation can respond to the damage caused by Semeru, one of the most powerful volcanic eruptions on Java island. The study areas were 2 regions that had been impacted by the Semeru lava flow for the period of 2004–2021. Based on the results, the ecosystem recovery of Semeru post-eruption was achieved within 5 years. During this time, the vegetation succession rate, as measured by vegetation cover, increased nearly ten folds. The post-eruption ecosystem recovery was indicated by the ecosystem transformation from a damaged ecosystem indicated by a lava-dominated surface to one with the presence of vegetation and hardened lava. The recovered ecosystem in Semeru's posteruption was composed of solid lava covers (39%), liquid lava (34%), and vegetation covers (27%).Then, the presence of vegetation and its succession rate can be used as a proxy of ecosystem recovery after a vast volcanic eruption.

Volcanic Eruptions on Mars, Lava Flow Morphology, and Thermodynamics

2021 ◽  
pp. 71-94
Author(s):  
Caitlin Ahrens ◽  
Vincenzo Cataldo ◽  
Giovanni Leone
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Flow Morphology

scholarly journals New Insights of Geomorphologic and Lithologic Features on Wudalianchi Volcanoes in the Northeastern China from the ASTER Multispectral Data

2019 ◽  
Vol 11 (22) ◽  
pp. 2663 ◽  
Author(s):  
Han Fu ◽  
Bihong Fu ◽  
Yoshiki Ninomiya ◽  
Pilong Shi
Keyword(s):  
Lava Flow ◽  
Thermal Emission ◽  
Imaging System ◽  
Three Dimensional ◽  
Volcanic Eruptions ◽  
Northeastern China ◽  
Fault System ◽  
Flow Index ◽  
Multispectral Data ◽  
Relative Dating

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imaging system onboard NASA’s (National Aeronautics and Space Administration’s) Terra satellite is capable of measuring multispectral reflectance of the earth’s surface targets in visible and infrared (VNIR) to shortwave infrared (SWIR) (until 2006) as well as multispectral thermal infrared (TIR) regions. ASTER VNIR stereo imaging technique can provide high-resolution digital elevation models (DEMs) data. The DEMs data, three-dimensional (3D) perspective, and ratio images produced from the ASTER multispectral data are employed to analyze the geomorphologic and lithologic features of Wudalianchi volcanoes in the northeastern China. Our results indicate that the 14 major conical volcanic craters of Wudalianchi volcanoes are arranged as three sub-parallel zones, extending in a NE (Northeast) direction, which is similar to the direction of regional fault system based on the ASTER DEMs data. Among the 14 volcanic craters in Wudalianchi, the Laoheishan, and Huoshaoshan lavas flows, after the historic eruptions, pouring down from the crater, partially blocked the Baihe River, which forms the Five Large Connected Pools, known as the Wudalianchi Lake. Lithologic mapping shows that ASTER multispectral ratio imagery, particularly, the Lava Flow Index (LFI) (LFI = B10/B12) imagery, can clearly distinguish different lava flow units, and at least four stages of volcanic eruptions are revealed in the Wudalianchi Quaternary volcano cluster. Thus, ASTER multispectral TIR data can be used to determine relative dating of Quaternary volcanoes in the semi-arid region. Moreover, ASTER 3D perspective image can present an excellent view for tracking the flow directions of different lavas of Wudalianchi Holocene volcanoes.

scholarly journals The Estimation of Lava Flow Temperatures Using Landsat Night-Time Images: Case Studies from Eruptions of Mt. Etna and Stromboli (Sicily, Italy), Kīlauea (Hawaii Island), and Eyjafjallajökull and Holuhraun (Iceland)

2020 ◽  
Vol 12 (16) ◽  
pp. 2537 ◽  
Author(s):  
Ádám Nádudvari ◽  
Anna Abramowicz ◽  
Rosanna Maniscalco ◽  
Marco Viccaro
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Lava Flows ◽  
Spectral Radiance ◽  
Night Time ◽  
Blue Band ◽  
Hawaii Island ◽  
Mt Etna

Using satellite-based remote sensing to investigate volcanic eruptions is a common approach for preliminary research, chiefly because a great amount of freely available data can be effectively accessed. Here, Landsat 4-5TM, 7ETM+, and 8OLI night-time satellite images are used to estimate lava flow temperatures and radiation heat fluxes from selected volcanic eruptions worldwide. After retrieving the spectral radiance, the pixel values were transformed into temperatures using the calculated calibration constants. Results showed that the TIR and SWIR bands were saturated and unable to detect temperatures over the active lava flows. However, temperatures were effectively detected over the active lava flows in the range ~500–1060 °C applying the NIR-, red-, green- or blue-band. Application of the panchromatic band with 15 m resolution also revealed details of lava flow morphology. The calculated radiant heat flux for the lava flows accords with increasing cooling either with slope or with distance from the vent.

scholarly journals Multiscale Modeling of Convection and Pollutant Transport Associated with Volcanic Eruption and Lava Flow: Application to the April 2007 Eruption of the Piton de la Fournaise (Reunion Island)

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 507
Author(s):  
Jean-Baptiste Filippi ◽  
Jonathan Durand ◽  
Pierre Tulet ◽  
Soline Bielli
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Surface Fluxes ◽  
Piton De La Fournaise ◽  
Complex Interactions ◽  
Local Modification ◽  
High Concentrations ◽  
Thermal Flows ◽  
Better Than ◽  
Good Agreement

Volcanic eruptions can cause damage to land and people living nearby, generate high concentrations of toxic gases, and also create large plumes that limit observations and the performance of forecasting models that rely on these observations. This study investigates the use of micro- to meso-scale simulation to represent and predict the convection, transport, and deposit of volcanic pollutants. The case under study is the 2007 eruption of the Piton de la Fournaise, simulated using a high-resolution, coupled lava/atmospheric approach (derived from wildfire/atmosphere coupled code) to account for the strong, localized heat and gaseous fluxes occurring near the vent, over the lava flow, and at the lava–sea interface. Higher resolution requires fluxes over the lava flow to be explicitly simulated to account for the induced convection over the flow, local mixing, and dilution. Comparisons with air quality values at local stations show that the simulation is in good agreement with observations in terms of sulfur concentration and dynamics, and performs better than lower resolution simulation with parameterized surface fluxes. In particular, the explicit representation of the thermal flows associated with lava allows the associated thermal breezes to be represented. This local modification of the wind flow strongly impacts the organization of the volcanic convection (injection height) and the regional transport of the sulfur dioxide emitted at the vent. These results show that explicitly solving volcanic activity/atmosphere complex interactions provides realistic forecasts of induced pollution.

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

Sign in / Sign up

Export Citation Format

Share Document