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52 Cards in this Set
- Front
- Back
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Volcano |
Quiet and explosive |
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Volcanism |
Geolgic process involved in eruptions |
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Volcanic Craters |
Bowl or circular shaped depression around the vent |
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Materials extruded during eruption |
Gases, Liquids, solids |
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Volcanic Gases |
1-9% of most magmas are gases 50-80% water vapor, CO2, N2, S and others Relationship to explosivity |
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Explosiveness of volcanoes |
Amount of gas in lava. How easily this gas can escape the lava |
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Mafic Lava |
Low viscosity, gases escape easy (lava flow) |
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Felsic lava |
High viscosity, colder, pressure builds up (Explosive) |
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Pyroclastic Material |
Tephra dust-1/1000 mm ash-<2 mm cinders-2-64 mm bombs->64 mm |
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Cinder cone |
33 degrees may represent final eruptive stages |
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Caldera |
Volcano falls in at the top cause a pocket that can hold water sometimes |
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Shield volcano |
2-10 degrees |
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Composite volcano |
built up by multiple explosions |
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Lahars |
Muddy like slush that pours down the side of volcanos |
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Lava dome |
high viscosity felsic magmas steep sided |
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Pyroclastic flows |
High gas content fast moving (100 mph) hot 800c glowing cloud |
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VEI (volcanic explosivity index) |
-0 to 8 -based on volume of material explosively ejected, height of eruption plume -Volume of lava, human and property damage are not considered - Duration is widely variable, from days to years |
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Volcano monitoring |
-physical and chemical changes -While timely warnings have been issued in the past, volcanoes remain unpredictable and only a few are regularly monitered |
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Predicting eruptions |
Satellite temperature |
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Distribution of volcanoes |
95% are at or near plate boundaries. Pacific surrounded by 80% of all volcanoes. |
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Intraplate Volcanism |
Hot spots that volcanos pass over and then die off when they are no longer above the hot spot. |
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Weathering and erosion |
Physical weathering Chemical weathering |
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Mechanical weathering |
Retains original composition Increase surface area |
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Frost wedging |
When water gets in cracks and freezes causing the rocks to expand |
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Exfoliation |
Pressure under surface releases causing the ground to expand |
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Thermal expansion and contraction |
Heat causes rocks to expand and contract |
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Animal weathering |
things such as worms can cause burrows with effect the land |
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Plant weathering |
Plants cause both physical and chemical do to expanding of roots and decaying of plant life. |
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chemical weathering |
changes in the chemical composition of minerals and rocks that are unstable at the earth's surface -solution -oxidation -hydrolysis |
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Factors in weathering |
Climate (water and tempature) Time (more time=more weathering Organisms (Plants, Animals, Bacteria) Mineralogy (Bowens's Reaction Series) |
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What is soil |
25% air 25% water 45% mineral matter 5% organic matter |
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O Horizon |
Organic matter
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A horizon |
Top soil, intense biological activity |
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B Horizon |
Subsoil, zone of accumulation |
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C Horizon |
Little organic matter partially altered parent rock |
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Factors controlling soil formation |
Parent material -grain size -compsition Topography Climate Vegetation Time |
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Topography |
the arrangement of the natural and artificial physical features of an area.
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Climate and vegetation |
reaction 2x increase with each 10c increase in temperature |
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Sedimentary Rocks |
-Weathering --Erosion ---Transportation (running water, wind, glacial ice) ----Deposition (in various environments such as rivers, deltas, beaches) -----Lithification (compaction, cementation) |
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Sedimentary rock |
thin layer, barely 5% of the earth's crust 75% of exposed rocks on earth |
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Pebble |
2-64 mm Loose-Gravel Consolidated-Conglomerate or Breccia |
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Sand |
0.063-2 mm Loose-Sand Consolidated-Sandstone |
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Silt |
0.004-0.063 Loose-Silt Consolidated-Siltstone |
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Clay |
<0.004 mm Loose-Clay Consolidated- Claystone, Mudstone, and shale |
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Wind transport |
fine grained Least viscous well sorted sand |
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Ice transport |
All Sizes intermediate viscosity transports gravel |
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Water transport |
all sizes high viscosity typically poorly sorted |
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How do sediments turn into rock |
compaction cementation crystallization |
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Detrital |
-Consist of fragments of sedimentary, metamorphic, and igneous rocks -Pieces can have sizes from fist size to barely visible: Classification-names -Silicates(there are lots them, resistance to weathering) |
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Silkstone |
Like mudstone, but grains barely visible |
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Mudstone |
Clay minerals and mica <0.004 mm low energy |
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Coal |
Compacted peat |
