Decreases in surface temperature of a few tenths of a degree C for several years following volcaniceruptions are primarily a result of the sulfate aerosols, rather than of the silicate dust. The similarity in the atmospheric response after
these three eruptions supports the idea of limiting mechanisms on volcanic stratospheric-aerosol loading, which is suggested by microphysical processes of aerosol particles. Fluctuations in stratospheric aerosol optical depth seem to be controlled to a large
degree by high-intensity sulfur-rich eruptions (e.g., Agung, 1963), which may however be relatively small in total ejecta volume. Such eruptions leave little geologic record, but appear as acidity peaks in polar ice cores.
Greetings from Iceland. Ash-falls and volcanic aerosols in Scandinavia
Atmosphère ; Aérosol volcanique ; Catastrophe ; Cendre volcanique ; Eruption volcanique ; Etude diachronique ; Europe ; Europe du Nord ; Géographie de l'Europe ; Islande ; Pollution ; Scandinavie ; Volcanisme
A brief account of ash-falls and aerosols from historical volcaniceruptions in Iceland that have affected Scandinavia is given with special reference to the noxious effects of aerosols from the Lakagigar eruption of 1783 registered in contemporary
A group of Ar-K dating data of volcanic rocks in Taiwan Island is listed in this paper, which clarifies the data of volcanic activity. This volcanic activity is closely related with plate movement since Mesozoic. Now there are still manifestations
of volcanic actions such as hot springs or fumaroles or solfataras.
New radiocarbon dates on charcoal incorporated in proximal airfall deposits indicate the largest late Pleistocene eruption from the Mt. Edgecumbe volcanic field in Southeast Alaska occurred ca. 11,250 yr B.P. The more precise dating of the principal
Based on observations, the A. concluded that the possible continuation of the volcanic activity in the Carpathian-Pannonian region is not just a pure speculation, but is supported by scientific data. Thus, detailed, integrated researches
on the possible future volcanism are crucial. - (AM)
Atmospheric aerosol loading and transport due to the 1783-84 laki eruption in Iceland, interpreted from ash particles and acidity in the GISP2 ice core
By using major ion, microparticle, and stable-isotope data obtained from ice cores, it is possible to assess the degree of atmospheric loading and potential climatic importance of major volcaniceruptions that occured prior to 1880. The AA. have
identified both silicate ash particle and sulfuric acid fallout from the 1783 Laki eruption in Iceland in the Geenland Ice Sheet Project 2 (GISP2) firn and ice core collected in 1989. The AA. use this information, coupled with available information
on the Laki event, to reassess atmospheric conditions following this major 18th century eruption.
Alors que l'influence de l'éruption du volcan islandais Laki sur le climat de l'Eurasie et du Nord-Est du Canada est bien documentée, le dépouillement des observations d'un astronome de l'époque permet pour la première fois de démontrer des
Innovation and diffusion of sand- and gravel-mulch agriculture in the American Southwest : a product of the eruption of sunset crater
Hommes et volcans
Agricultural practice ; Agriculture ; Arizona ; Historical geography ; New Mexico ; Prehistory ; United States of America ; Volcaniceruption ; Volcanism
Geomorphological mapping with interest in the extent of glacial erosion giving, at the same time, a comprehensive treatment to a possible danger threatening Quito in case of a volcaniceruption of Pichincha. (MS).
Alakmérési vizsgalatok a Karpatok vulkani vonulatanak egykori kitorési kozpontjain Morphometric investigations on the former eruption centres of the Carpathian volcanic range
The forms of the former eruption centres - craters and calderas - were grouped on the basis of index numbers of their diameters and inner depths. This resulted a better and newer differentiation of these forms and the support of formerly remote
Description détaillée de l'éruption de l'Hekla. En appendice (p.33-34), le tableau précis des tremblements de terre ayant accompagné l'éruption, ainsi que la température et la composition chimique des émanations issues du volcan (p.45-51). (J. C
This work deals with the dating of Mount Etna lava flows and eruptive fissure deposits to the last four millennia following field investigations and stratigraphic data. In most cases the results allow attributing ages to the historical period
, although 2 flows are shown to be prehistoric. Although 60% of these volcanics exhibit ages comprised between 700 AD and 1850, only one (1285) is mentioned by contemporary written accounts. The AA. conclude that i) historical documents alone are insufficient
to reconstruct a coherent sequence of eruptions, and ii) a multidisciplinary approach is necessary to obtain a comprehensive eruptive history of such a very active volcano. Thanks to these new archeomagnetic and 226Ra-230Th data coupled with stratigraphic data
, a comprehensive volcanic history of the still-outcropping Mount Etna volcanics is now available for the last 2,400 years. - (NF)