Geology

Earth Science Related Book

“The Wave” by Suzan Casey

Rating:

Interest and Excitement: 5/5

Scientific Content: 3/5 (I would have preferred a bit more science in the book, specifically more information about the math behind wave mechanics)

Reasons For Choosing This Book:

This book would incorporate earth science, oceanography, physics and climate change into an exciting hunt for rough waves. For Earth Science, one could learn about the three ingredients needed to produce large waves; Sustained winds, a large surface area and duration of wind. These three ingredients will allow waves to grow larger and combined (constructively) to create larger waves. There are places on the planet that favor these conditions and this book explores some of them through the eyes of tanker-ship captains, oil rig employees and of course, big wave surfer Laird Hamilton. Famous big-wave surfer Laird Hamilton chases these waves all around the world, and the surfer’s perspective keeps this book interesting and exciting. He is the only person to have possibly ridden a 100’ wave, but there were no documentations from that day. He rode the wave at a location off of Maui’s north shore called “Egypt’s”, located near another famous break called “Jaws.”

Summary:

This book is about the hunt for Rough Waves, and the story of how they have elevated from exaggerated Captain’s tales to a scientific study today.  For decades (if not centuries), sailors have witnessed ocean conditions that at the time were believed to defy physics, and these waves were dismissed as exaggerations by captains. Nobody had ever captured any scientific evidence on the existence of these waves until 15 years ago.

NY Times Review

“Surf’s Up” By HOLLY MORRIS Published: September 17, 2010

“Susan Casey examines big waves from every angle, and goes in deep with those who know the phenomenon most intimately: mariners, wave scientists and extreme surfers.

These supposed 100-foot waves were dismissed as exaggerations, and many captains were reluctant to speak of witnessing one for fear of being thought of as a “hack” captain. This changed when a rig off the northern coast of Sweden was hit by a 90’+ wave in a storm and was recorded by an instrument mounted on the rig. With this new “hard” data, scientists were forced to look at these waves with a new seriousness.

“But witnesses of a 100-foot wave at close range rarely lived to tell, and experts dismissed stories about these waves because they seemingly violated basic principles of ocean physics. It was only 10 years ago, when the British research ship Discovery was caught in a punishing North Sea storm, that legend became scientific fact. The battered ship straggled into dock, and grateful scientists unlashed themselves from their bunks, tiptoeing around bashed furniture and shattered glass. They discovered that despite the Armageddon-like conditions, the ship’s research collecting devices had kept on working. And indeed they recorded seas 60 feet high, with some wave faces spiking at 90 feet and higher. The evidence was in, and soon became overwhelming as satellites began confirming that rogue waves thrust out of the world’s oceans with some frequency.”

 NY Times Review

Relevance:

This book poses a good question: Is climate change leading to more rouge waves and higher energy seas?

Susan Casey also explores this question by interviewing many scientists from around the world. Overwhelmingly, scientists agree that warmer climates will bring bigger waves, and the correlations are seen through hind-casting weather reports and occurrences of tankers sunk by these waves.

Application:

If I were teaching Earth Science, I would not make this book a direct assignment because of the lack of “hard” science and because of the time it would take to administer the assignment. I would use this book as an extra credit assignment and have students present a short, oral report about what they thought of the book. I would have students relate the content to something learned in Earth Science, such as Oceanography, wave propagation, climate change or wind patterns. This book would bring more excitement to these areas because the stories or rouge waves are true and only recently have been revealed.  Susan Casey does a great job at bringing multiple perspectives about these waves to the reader. 

Matthew Keyes

Geological Sciences

Undergraduate Research Project

Abstract

Loihi is the youngest volcano in the Hawaiian chain, located ~1 km below sea level and ~35 km south of the island of Hawaii.  The chemical compositions of its lavas represent magma sources within the mantle plume.   When studying these chemical and isotopic compositions, it is important to distinguish between signatures representing mantle sources from ones produced by contamination processes.  Contamination can occur as ascending melts interact with the lithosphere, ocean crust and inside the volcano edifice. Because Loihi is a submarine volcano, seawater is yet another potential source for magma or lava contamination.

            Hydrothermal circulation occurs within Loihi Seamount and allows seawater to interact with erupted basalts.  Previous studies have shown that Cl and H₂O enrichments found in Loihi glasses are produced by assimilating seawater brines (Kent, 1999).  Evaporating seawater at the magma-water interface, or within hydrothermal systems produces these brines, which are then deposited in small cracks and fissures in the country rock.  Assuming this model would imply that alteration of these glasses occurred by bulk assimilation of seawater-brine, in which all constituents of seawater become assimilated into the magma. Although this mechanism supports Cl and H₂O data, (²³⁴U/²³⁸U) disequilibria cannot be produced by this mechanism.

            Excesses of ²³⁴U relative to ²³⁸U (up to ~1%) have been discovered in fresh volcanic glasses erupted from Loihi Seamount using high-precision MC-ICP-MS techniques. The origin of the seawater ²³⁴U signature is unclear.  The main purpose of this study is to try to determine if the seawater ²³⁴U signature is related to crustal contamination with seawater-altered rocks surrounding Loihi’s magma chamber or if it represents contamination of the glass surface due to interaction with seawater during or after eruption.  To test this hypothesis, eight glass samples were measured for their uranium isotope ratios before and after leaching. If leaching removes the excess ²³⁴U, then the uranium was deposited on the glass surface only during seawater interaction with post eruptive basalts. If the excess ²³⁴U is not removed, then assimilation of seawater-altered rocks in the magma chamber is the preferred mechanism.

            In this study eight previously analyzed samples (treated with only a brief cleaning with 2M HCl) were subjected to a rigorous leaching process (6M HCl, 0.5M oxalic acid-2% H₂O₂, and 1M HCl-2% H₂O₂) and analyzed for their uranium isotope ratios.  When compared to the unleached samples, leaching failed to remove the excess ²³⁴U.  This finding suggests the uranium was assimilated by crustal contamination of seawater-altered rocks surrounding Loihi’s magma chamber.  This process is an important one because it may be fundamental to all ocean island settings.  If the mechanism can be more clearly understood, then future analyses of glasses from these settings can be corrected for seawater alteration.  This is important to geochemists because the goal of analyzing basalts from OIB settings is to understand mantle sources and processes.