Geography 180
Supplemental Reading
Plate Tectonics / Sea Floor Spreading
“Soundings: The story of the remarkable woman who mapped the ocean floor”
Cast of Characters:
Marie Tharp – first person to map the ocean floor; multiple degrees including geology and math; Lamont cartographer
Bruce Heezen – researcher at Lamont; Marie’s supervisior
Maurice “Doc” Ewing – pioneer in geo-physics; used physics to study geology instead of chemistry
Lamont Geological Observatory – geo-physical laboratory of Colombia University
Atlantis – Lamont research ship; only males could sail/research onboard
Harry Hess – Chair of Princeton Geology Department; rival to Colombia
You will be reading a section of the biography of Marie Tharp by Hali Felt (2012). As mentioned in class, Marie Tharp is
the unsung hero of plate tectonics. It was her work that recognized the rift in the Mid-Atlantic Ridge that provided the
physical evidence needed to support continental drift. Continental drift was heavily derided by geologists at the time,
and so her evidence was radical and controversial. The section you are reading deals with the work that leads to her
discovery, and the subsequent events within geology when this work is presented. This reading deals with scientific
research, plate tectonics and the role of gender in academia.
I suggest you read through once, noting the following points. You do not need to formally answer them.
Chapter 10
 Why is it not a small question when Bruce asks Marie what she thinks about the sounding records?
 How were they collected?
 Identify the northern most and southernmost transects on a map.
 Abyssal plains – large flat areas of the ocean floor covered with sediment, which make them the flattest areas on
the earth’s surface.
 Vertical Exaggeration – Rise over Run / Slope over Distance
 Why was working on such a large surface an advantage?
 What was Bruce afraid of after he sees Marie’s map?
 What was the prevailing opinion of continental drift in 1952?
Chapter 12
 When Bruce presents these findings at a conference in 1957, what
comments is he recalling?
 What does Henry Hess say at the conclusion of his presentation?
 What is Jacques Cousteau’s do to disprove it the existence of the rift?
 Tension = divergence
Read the chapters a second time, and answer the following questions using specific events and examples.
1.
Summarize the process / steps involved in identifying the rift valley in the Mid-Atlantic Ridge.
2.
Explain the biases (gender and academic) that prevent the acceptance of Tharp’s discovery.
3.
Why was Marie Tharp uniquely qualified to make this discovery?
4.
What did you learn about the process of scientific inquiry and results?