DAILY WARMUP

1
DAILY WARM-UP

• Write one thing you know about Charles Darwin.
• Define what you think a seamount is.
• Rank the following pictures from youngest to
  oldest.

A B
C
2
RELATIVE AGE
The approximate age of something determined by
comparing whether it is older or younger than
something similar.
A B
C

• older
• than ?

• older
• than ?

3
WHAT IS A SEAMOUNT?
A mountain on the ocean floor that does not reach
the surface.
4
BUILDING REEFS
Ridges formed of live coral animals build-up on
the skeletons of dead coral animals found in
tropical oceans.
5
MORPHOLOGY

• Morphology is the study of the origin of rocks as
  well as their formation and composition.
• Morphology can describe the form and structure
  of a feature, such as a seamount or coral reef.

Typical conical volcanic morphology of Mount
Fuji, Japan
6
RELATIVE DATING

• Charles R. Darwin (1809-1882)
• James D. Dana (1813-1895)

7
CHARLES R. DARWIN
Scientist aboard H.M.S Beagle voyage in 1831 and
most famous for ideas on natural selection and
evolution.
8
CHARLES R. DARWIN
But Darwin also wrote about evolution of coral
reefs.
9
CHARLES R. DARWIN
Hypothesized about the relative age progression
of coral reefs in the ocean.

• Coral reefs begin as fringing reefs.
• Subsidence occurs and barrier reefs form.
• Even more subsidence and an atoll forms.

10
Darwin based his hypotheses on above sea surface
observations.
Now we know what it looks like below the surface
of the ocean, but in 1831 Darwin did not!
11
JAMES D. DANA
Expanded on Darwins work on evolution of coral
reefs and islands.
12
RELATIVE AGE DATING

• Darwin and Dana were practicing relative age
  dating.
• Rather than providing actual ages for the coral
  and islands they inferred that one was older than
  another based on appearance.

13
LIFE CYCLE SEAMOUNTS
Hot lava erupts to make a seamount.
14
LIFE CYCLE SEAMOUNTS
Continued eruptions and seamount becomes an
island.
15
LIFE CYCLE SEAMOUNTS
As the eruptions stop lava cools.
16
LIFE CYCLE SEAMOUNTS
Eventually plants begin to grow on the cooled
lava.
17
LIFE CYCLE SEAMOUNTS
Soon the entire island has vegetation covering
the lava.
18
LIFE CYCLE SEAMOUNTS
Eventually the island sinks. Now it is a seamount.
19
CHARLES R. DARWIN
The evolution of coral reefs happens at the same
time.