Chapter 16 Vocabulary Flashcards
geology
Study of the earth’s dynamic history. Geologists study and analyze rocks and the features and processes of the earth’s interior and surface
core
Inner zone of the earth. It consists of a solid inner core and a liquid outer core (3)
mantle
Zone of the earth’s interior between its core and its crust (2)
crust
Solid outer zone of the earth. It consists of oceanic crust and continental crust (1)
convection cells/currents
internal heat pushes rock upwards and down
mantle plumes
type of movement that occurs with mantle
tectonic plates
Various-sized areas of the earth’s lithosphere that move slowly around with the mantle’s flowing asthenosphere. Most earthquakes and volcanoes occur around the boundaries of these plates
lithosphere
Outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth’s plates
plate tectonics
Theory of geophysical processes that explains the movements of lithospheric plates and the processes that occur at their boundaries
continental drift
- concept that became widely accepted by geologists in the 1960s
- continents have split and joined as plates have very slowly drifted thousands of kilometers back and forth across the planet’s surface
divergent plate boundary
- lithospheric plate boundary
- where the plates move apart in opposite directions
convergent plate boundary
- lithospheric plate boundary
- where the plates are pushed together by internal forces.
transform fault
- lithospheric plate boundary
- occurs where plates slide and grind past one another along a fracture (fault) in the lithosphere
- most found on ocean floor, but some on land
erosion
- external process
- process by which material is dissolved, loosened, or worn away from one part of the earth’s surface and deposited elsewhere
- flowing streams cause most erosion
- wind blowing particles causes it also
weathering
physical, chemical, and biological processes that break down rocks and minerals into smaller particles that can be eroded.
physical/mechanical weathering
a large rock mass s broken into smaller fragments.
frost wedging
- most important agent of mechanical weathering
- water collects in pores and cracks of rock, expands upon freezing, and splits off pieces of the rock
chemical weathering
- one or more chemical reactions decompose a mass of rock
- most chemical weathering involves a reaction of rock material with oxygen, carbon dioxide, and moisture
biological weathering
the conversion of rock minerals into smaller particles through the action of living things
ex.) lichens produce acids that can chemically weather rocks
earthquake
shaking of the ground resulting from the fracturing and displacement of rock, which produces a fault, or from subsequent movement along the fault
Richter scale
- scientists use it
- each unit represents an amplitude 10 times greater than the next smaller unit
- measures earthquakes
aftershocks
-after a big shock that gradually decreases in frequency over a period of up to several months
foreshocks
-occur seconds or up to weeks before the main shock
tsunamis
huge water waves (tidal waves)
volcano
vent or fissure in the earth’s surface through through which magma, liquid lava, and gases are released into the environment
fissure
long crack
ejecta
debris ranging from large chunks of lava rock to ash that may be glowing hot