PYROCLAST/SNOW INTERACTIONS AND THERMALLY DRIVEN SLURRY FORMATION. PART 1: THEORY FOR MONODISPERSE GRAIN BEDS
- DSpace Home
- →
- Геология России
- →
- ELibrary
- →
- View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.
dc.contributor.author | Walder J.S. | |
dc.date.accessioned | 2021-01-25T04:55:58Z | |
dc.date.available | 2021-01-25T04:55:58Z | |
dc.date.issued | 2000 | |
dc.identifier | https://elibrary.ru/item.asp?id=987037 | |
dc.identifier.citation | Bulletin of Volcanology, 2000, 62, 2, 105-118 | |
dc.identifier.issn | 0258-8900 | |
dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/23762 | |
dc.description.abstract | Lahars are often produced as pyroclastic flows move over snow. This phenomenon involves a complicated interplay of mechanical and thermal processes that need to be separated to get at the fundamental physics. The thermal physics of pyroclast/snow interactions form the focus of this paper. A theoretical model is developed of heat- and mass transfer at the interface between a layer of uniformly sized pyroclasts and an underlying bed of snow, for the case in which there is no relative shear motion between pyroclasts and snow. A microscale view of the interface is required to properly specify boundary conditions. The physical model leads to the prediction that the upward flux of water vapor - which depends upon emplacement temperature, pyroclast grain size, pyroclast-layer thickness, and snow permeability - is sometimes sufficient to fluidize the pyroclasts. Uniform fluidization is usually unstable to bubble formation, which leads to vigorous convection of the pyroclasts themselves. Thus, predicted threshold conditions for fluidization are tantamount to predicted thresholds for particle convection. Such predictions are quantitatively in good agreement with results of experiments described in part 2 of this paper. Because particle convection commonly causes scour of the snow bed and transformation of the pyroclast layer to a slurry, there exists a "thermal scour" process for generating lahars from pyroclastic flows moving over snow regardless of the possible role of mechanical scour. | |
dc.subject | PYROCLASTIC FLOWS | |
dc.subject | SNOW | |
dc.subject | LAHARS | |
dc.subject | EROSION | |
dc.subject | HEAT TRANSFER | |
dc.subject | FLUIDIZATION | |
dc.title | PYROCLAST/SNOW INTERACTIONS AND THERMALLY DRIVEN SLURRY FORMATION. PART 1: THEORY FOR MONODISPERSE GRAIN BEDS | |
dc.type | Статья |
Files in this item
Files | Size | Format | View |
---|---|---|---|
There are no files associated with this item. |
This item appears in the following Collection(s)
-
ELibrary
Метаданные публикаций с сайта https://www.elibrary.ru