ESS 101 CERTIFICATION SCRIPT 2026
COMPLETE QUESTIONS AND CORRECT
ANSWERS
◉Isostatic equilibrium. Answer: lithosphere "floats" on a partially
melted asthenosphere, similar to a raft floating on water. The
lithosphere is in isostatic equilibrium with the asthenosphere.
◉Does the thin, dense, ocean lithosphere float lower or higher than
the continental lithosphere?. Answer: The ocean lithosphere floats
lower than the continental lithosphere which is less dense (2.6
g/cm3) and thicker (40-70km).
◉What happens when an ice sheet is placed on the lithosphere?.
Answer: it will isostatically depress the lithosphere relative to the
asthenosphere. When the ice melts, the lithosphere isostatically
rebounds.
◉What can plate tectonics explain?. Answer: 1. the presence of
volcanic mid ocean ridges.
2. volcanic mountain chains around the pacific ocean basin.
3. the matching coastlines of africa and europe with south america
and north america.
,4. matching ancient rock assemblages of the adjacent continents. ex:
climate belts from the Paleozoic aged earth are preserved in the rock
record.
5. explain the presence of paleozoic aged (300 Ma old) glacial till
deposits found in South America, Africa, India, Australia, and
Antarctica today.
7. the spatial distribution of volcanoes around the world, including
the explosive volcanoes rimming the pacific ocean basin (ring of
fire).
8. explain the spatial distribution of seismic (earthquakes) activity
around the world including the depth of their respective foci.
◉What can paleontological evidence support?. Answer: plate
tectonics and plate motions. fossil evidence of land animals and
plants that lived during the paleozoic era are now found on
disparate continents separated by 1000s of miles of ocean water.
◉Divergent margins. Answer: shallow-focused
◉convergent margins. Answer: shallow to deep focused EQs
◉When does geothermal activity most often occur?. Answer: near
tectonic plate boundaries and is less common in the interior of
continents.
,◉Where does geothermal activity occur in the interior of
continents?. Answer: East Africa, Great Basin of USA, and can be
explained in a tectonic context.
◉To understand plate tectonics, one must. Answer: understand the
dynamics between the solid, rigid lithosphere that is "floating" on a
partially molten asthenosphere.
◉The solid lithosphere is composed of what?. Answer: continental
and ocean crust and the uppermost mantle.
◉plastic asthenosphere. Answer: composed of the upper mantle and
is at or near the melting temperature for upper mantle rock
◉What is the plate tectonic system driven by?. Answer: convection
within the asthenosphere. convective upwelling of the
asthenosphere along divergent margins produces new ocean
lithosphere, while it is subducted along convergent margins.
◉important graph look at on phone or presentation slide. Answer:
look at it and memorize it, understand it.
◉two main ways in which melting occurs in the mantle. Answer:
look at graph and understand it
, ◉what is basaltic ocean crust produced by?. Answer: It is produced
by partial melting of the garnet-peridotite asthenosphere. As the
basaltic magma rises it becomes more fluid (liquid).
◉Why does basaltic magma become more fluid as it rises?. Answer:
Think about slope of melting temperature curve with decreasing
pressure versus actual temperature curve. Melting temp decreases
at a rate greater than actual temp. Actual temp is higher than
melting temp at surface. Why does this occur: when magma reaches
surface, its much hotter than the melting temp at surface??
◉Divergent margins. Answer: first form under continental crust
because of the insulating properties. Eventually, the upwelling
basaltic magma will completely melt through the overlying
continental crust and an incipient ocean basin will form and the two
segments of continental crust will rift apart.
◉When the continental crust is first heated at its base what will its
topographic expression look like at the surface?. Answer: Think of
East africa. It will rise and get higher.
◉sea floor spreading. Answer: The ocean floor becomes wider as the
new ocean lithosphere is produced at the divergent margin.
◉What does the east african rift zone represent?. Answer: a
continental rift.
COMPLETE QUESTIONS AND CORRECT
ANSWERS
◉Isostatic equilibrium. Answer: lithosphere "floats" on a partially
melted asthenosphere, similar to a raft floating on water. The
lithosphere is in isostatic equilibrium with the asthenosphere.
◉Does the thin, dense, ocean lithosphere float lower or higher than
the continental lithosphere?. Answer: The ocean lithosphere floats
lower than the continental lithosphere which is less dense (2.6
g/cm3) and thicker (40-70km).
◉What happens when an ice sheet is placed on the lithosphere?.
Answer: it will isostatically depress the lithosphere relative to the
asthenosphere. When the ice melts, the lithosphere isostatically
rebounds.
◉What can plate tectonics explain?. Answer: 1. the presence of
volcanic mid ocean ridges.
2. volcanic mountain chains around the pacific ocean basin.
3. the matching coastlines of africa and europe with south america
and north america.
,4. matching ancient rock assemblages of the adjacent continents. ex:
climate belts from the Paleozoic aged earth are preserved in the rock
record.
5. explain the presence of paleozoic aged (300 Ma old) glacial till
deposits found in South America, Africa, India, Australia, and
Antarctica today.
7. the spatial distribution of volcanoes around the world, including
the explosive volcanoes rimming the pacific ocean basin (ring of
fire).
8. explain the spatial distribution of seismic (earthquakes) activity
around the world including the depth of their respective foci.
◉What can paleontological evidence support?. Answer: plate
tectonics and plate motions. fossil evidence of land animals and
plants that lived during the paleozoic era are now found on
disparate continents separated by 1000s of miles of ocean water.
◉Divergent margins. Answer: shallow-focused
◉convergent margins. Answer: shallow to deep focused EQs
◉When does geothermal activity most often occur?. Answer: near
tectonic plate boundaries and is less common in the interior of
continents.
,◉Where does geothermal activity occur in the interior of
continents?. Answer: East Africa, Great Basin of USA, and can be
explained in a tectonic context.
◉To understand plate tectonics, one must. Answer: understand the
dynamics between the solid, rigid lithosphere that is "floating" on a
partially molten asthenosphere.
◉The solid lithosphere is composed of what?. Answer: continental
and ocean crust and the uppermost mantle.
◉plastic asthenosphere. Answer: composed of the upper mantle and
is at or near the melting temperature for upper mantle rock
◉What is the plate tectonic system driven by?. Answer: convection
within the asthenosphere. convective upwelling of the
asthenosphere along divergent margins produces new ocean
lithosphere, while it is subducted along convergent margins.
◉important graph look at on phone or presentation slide. Answer:
look at it and memorize it, understand it.
◉two main ways in which melting occurs in the mantle. Answer:
look at graph and understand it
, ◉what is basaltic ocean crust produced by?. Answer: It is produced
by partial melting of the garnet-peridotite asthenosphere. As the
basaltic magma rises it becomes more fluid (liquid).
◉Why does basaltic magma become more fluid as it rises?. Answer:
Think about slope of melting temperature curve with decreasing
pressure versus actual temperature curve. Melting temp decreases
at a rate greater than actual temp. Actual temp is higher than
melting temp at surface. Why does this occur: when magma reaches
surface, its much hotter than the melting temp at surface??
◉Divergent margins. Answer: first form under continental crust
because of the insulating properties. Eventually, the upwelling
basaltic magma will completely melt through the overlying
continental crust and an incipient ocean basin will form and the two
segments of continental crust will rift apart.
◉When the continental crust is first heated at its base what will its
topographic expression look like at the surface?. Answer: Think of
East africa. It will rise and get higher.
◉sea floor spreading. Answer: The ocean floor becomes wider as the
new ocean lithosphere is produced at the divergent margin.
◉What does the east african rift zone represent?. Answer: a
continental rift.
