1.
aa: jagged chunks of lava
2.
aftershocks: series of small tremors that follow an earthquake
3.
astronomy: study of the universe and beyond the earth
4.
atmosphere: gases surrounding the earth
5.
cavern: naturally formed underground chamber
6.
chemical bonds: forces that hold atoms together in a compound
7.
chemical weathering: breaking down of rocks by changing the chemical composition
8.
cinder cones: volcano with very steep, sloping sides
9.
climate: weather over an area for a long period of time
10.
composite volcano: volcano formed from alternating layers of lava and pyroclastic materials
11.
compression: strain that occurs when crustal rocks are squeezed together
12.
convergent boundary: plate boundary where the plates move toward each other
13.
core: center of the earth
14.
crater: funnel-shaped pit at the top of the a volcanic vent
15.
crust: outermost layer of the earth
16.
delta: accumulation of sediment where a stream enters a lake or ocean
17.
divergent boundary: plate boundary where the plates move away from each other
18.
epicenter: location on the earth's surface directly about the focus
19.
erosion: the process by which the products of weathering are transported
20.
floodplain: flat valley floor
21.
focus: point within the earth where an earthquake starts
22.
frost wedging: water seeps down into the cracks of rocks and freezes
23.
geology: study of the origin, history, and structure of the earth
24.
geyser: intermittent hot spring or fountain that shoots water in a column into the air
25.
humus: dark, organic material found in fully developed soil
26.
karst: landscapes formed from water that has dissolved underground
27.
mechanical weathering: breaking down of rocks into smaller pieces without changing the composition of the rocks
28.
Moho: Mohorovicic discontinuity
29.
oceanography: study of the earth's oceans
30.
pahoehoe: lava that looks like rope when cooled
31.
Pangaea: name means "all lands"
32.
Panthalassa: name means "all seas"
33.
pyroclastic materials: rock fragments ejected from a volcano
34.
rockslide: sudden movement of masses of loose rock and soil down the slope of a mountain
35.
seismogram: time record of earthquake activity
36.
shearing: strain that occurs when crustal rocks are pushed and pulled in opposite horizontal directions
37.
shield volcanoes: volcano with broad base and gentle, sloping sides
38.
soil horizons: soil layers or zones
39.
stream channel: course the water in a stream follows
40.
tension: strain that occurs when crustal rocks are pulled apart
41.
tributary: stream that empties into another stream
42.
trough: U-shaped valleys
43.
weather: atmospheric conditions over an area for a short period of time
44.
well: hole bored into the zone of saturation for the purpose of extracting water