Troubled Waters

Table of Contents

1. Frontmatter

2. Chapter 1. A Cautionary Scientific Tale and an Introduction to This Book

   Stephen J. Culver

   Abstract

   The unplanned collection of a small, nondescript rock in Senegal, west Africa leads to a story of how science and the acquisition of new knowledge does not necessarily progress in a series of straightforward steps. This cautionary tale is followed by an introduction that explains the purpose and content of this book, to explain to the general public, politicians, managers and policy makers how our coasts, important to us as places of not only inhabitation and vacation but also of natural resources and industry, are in crisis, in large part due to human activities. The human side of scientific research is emphasized and this book describes how geologists try to understand the workings of our varied coastal systems and what the future will bring for these beautiful and often wild parts of our planet.

3. Chapter 2. Buried Secrets of the North Carolina Coast, USA

   David J. Mallinson

   Abstract

   The Outer Banks Barrier Islands of North Carolina, USA are beautiful and dynamic coastal features with a long and complicated human history and geological story. The hard work of numerous university faculty, agency scientists and students have uncovered the geological secrets of this region. Using geophysical devices that reveal the underpinnings of the islands and estuaries, and collecting sediments and fossils to understand changes to the environments, we can see how the islands and estuaries responded to climate conditions and storm patterns in the past. Those past responses are informing us of what might be expected in the future given projected climate and sea-level changes. This is the story of the work that has been done to reveal the secrets of this coast.

4. Chapter 3. Time and Tide Wait for No Man

   Andrew C. Kemp, Benjamin P. Horton

   Abstract

   Relative sea level is the difference in height between the coast and sea surface. It changes across space and through time in response to many different physical processes operating on a range of scales. Using an example from North Carolina, USA, we introduce some of these key processes and explore how their importance varies on timescales from hours (e.g., hurricanes and tides) to millennia (e.g., ongoing subsidence of the coast). Below the salt marshes of North Carolina (and elsewhere) are sequences of sediment that accumulated over thousands of years and record relative sea-level changes. Geologists collect this sediment, establish its age and interrogate it to understand when and how relative sea level changed long before people began to make systematic measurements. This research shows that the rate of rise during the twentieth century was without precedent in ~2000 years.

5. Chapter 4. Barrier Island Breakdown: The Ephemeral Outer Banks of North Carolina

   Stephen J. Culver

   Abstract

   This chapter describes sudden coastal change that took place in North Carolina, USA 1200 years ago during a period of warmth in the northern hemisphere known as the Medieval Climate Anomaly. It explains how we know that this event occurred, and it describes the geologic tools that we used to reconstruct the event. A large segment of the Outer Banks barrier islands was flattened, probably by one or more strong hurricanes. Oceanic waters entered estuarine Pamlico Sound, which metamorphosed into an open Pamlico Bay. The tidal range increased, tidal currents increased in strength, salinity increased, and fish migrated as they adapted to new conditions. Human inhabitants of the region would also have had no choice but to adapt. Over 500 years the barrier islands were reconstructed and pre-storm conditions returned by the time the first Europeans landed on this coast in 1585. A similar series of events could occur once more in coastal North Carolina during the current period of global warming. Economic effects would be disastrous.

6. Chapter 5. A Different Kind of Sea-Level Story from Malaysia

   Peter R. Parham

   Abstract

   In many countries of Southeast Asia, the sea is the primary source of food and center of the community. Life is very simple and intertwined with the ocean’s moods. So many people depend on this sea, day after day, generation after generation, despite monsoons, typhoons, erosion and flooding, death and hardship. Surprisingly, little study had been undertaken to help these communities anticipate the impact of coastal change on their lives and livelihoods. My study of nearly every Malaysian island, shore and coastal plain stream allowed me to interpret past coastal influences and predict future impact. It also allowed me to experience this amazing country and her people under every conceivable circumstance, some warm or amusing, some perilous and some death-defying.

7. Chapter 6. What Lies Beneath? Revealing Coastal Processes Through Mapping

   J. P. Walsh

   Abstract

   Coastal areas are changing as a result of natural and human activities, and these dynamics create risks for citizens and communities. Science is needed to map and measure coasts and oceans, and many new tools exist to enhance our knowledge. In this chapter, some of the methods being employed around the world are discussed including GIS, multibeam sonar and aerial imaging. Stories from past and recent research are used to explain the approaches as well as their scientific and societal value. Weaving together experiences from ancient worlds, on distant shores and with crocodiles, I explain how and why we learn about what lies beneath the waves and along our shores.

8. Chapter 7. The Anthropocene, Wait, What? A Basque’s Coastal Experience Helps to Figure It Out

   Eduardo Leorri

   Abstract

   At the very end of the twentieth century I was working on my PhD project that included getting (knee) deep into the mud of the Bilbao Estuary (Northern Spain) to understand the environmental evolution of this system dramatically altered by anthropogenic activities. Almost concomitantly, a new term to describe the period during which humans have become major drivers of change was coined: “Anthropocene.” This chapter briefly narrates my experience as PhD student and how it led me to adopt this term to identify sediments reflecting predominantly human activities and why (in my opinion) this term is relevant.

9. Chapter 8. A Tale of Two Hydrogeology Problems in Coastal North Carolina

   Alex K. Manda

   Abstract

   This chapter highlights two tales describing the techniques scientists use to investigate how groundwater and surface water in coastal regions are threatened by saltwater intrusion. Crop production and water supply to communities are being increasingly affected. In the first tale, researchers document how they use computer models to determine the mechanisms by which saltwater intrusion is happening beneath a barrier island in North Carolina, USA, that is popular with tourists. The second tale, also from North Carolina, details the extent to which scientists will go to understand saltwater intrusion occurring in natural and artificial channels that traverse low-lying coastal regions.

10. Chapter 9. Drilling the North Carolina Coastal Plain – Discovering What Lies Beneath

    Kathleen M. Farrell

    Abstract

    This chapter explains how geologic environments of the Quaternary are explored by a field geologist who drills holes and collects core samples from the coastal plain of North Carolina, USA, and why these cores are windows into the sedimentary rock pile that lies beneath our Earth’s surface. It is the tale of one geologist who maps landforms and cores for stratigraphy not only because it’s so much fun, but also because society can benefit from the research findings—usually in the form of geologic maps and cross sections constructed from cores. Maps and cross sections can help us to identify surface water pathways and underground flowpaths, the size and scale of underground reservoirs and aquifers, and the distribution of economically valuable minerals. They can also be used to develop geologic hazard and groundwater vulnerability maps, for more effective land use planning.

11. Chapter 10. Earthquake-Driven Coastal Change: Ghost Forests, Graveyards and “Komodo Dragons”

    Andrea D. Hawkes

    Abstract

    Like Indonesia prior to the 2004 Indian Ocean earthquake and tsunami, much of the west coast of North America (northern California through Vancouver Island BC) has had no instrumentally or historically recorded great earthquakes and tsunamis. This lack of events is a veil of safety that the geologic record indicates is false. Analysis of sediments deposited by these events provides important information about prior and potential earthquake and tsunami characteristics (magnitude, frequency, runup, etc.) fundamental to having an informed population and hazard preparation and mitigation. Collecting these sediments requires fieldwork, my favorite part of the job, which often provides some unique experiences. In this chapter, ghost forests and a graveyard bookend paleoearthquake fieldwork in coastal Oregon and a dance with a ‘Komodo Dragon’ in coastal Malaysia makes sampling the 2004 Indian Ocean tsunami an experience I will never forget.

12. Chapter 11. A Scientist’s Personal 70-Year Discourse with Past, Present and Future Coastal Change

    Stanley R. Riggs

    Abstract

    This story tracks the growth and history of a coastal marine scientist and his efforts to teach coastal dynamics to generations of students and public for over 50 years. It also encapsulates an incredible journey through hundreds of million years, summarizing the story of oceans and their coastal systems that helped to build our North American continent. The journey begins in the Pleistocene glacial world in northern Wisconsin, travels back to the Ordovician beach deposits of the central Mid-West and to the rocky coasts of the northern Appalachian Mountains of New England, and then travels forward to the great Cretaceous Sea in the eastern Rocky Mountain region. However, the core of this story concerns the 200 million year history of the Atlantic Ocean and formation of the southeastern US coastal margin, characterized by continental shelf, barrier island, estuarine, and riverine systems. Human occupation of this region, which began over 10 millennia ago, has recently evolved into a force capable of manipulating and changing the character and processes of modern coastal systems. The story culminates with a discussion of the “perfect conflict” between expanding human populations and the natural dynamic nature of our coasts.

13. Chapter 12. Climate, Sea Level, and People – Changing South Florida’s Mangrove Coast

    G. Lynn Wingard

    Abstract

    South Florida’s coast is a land of contrasts that appeals to almost everyone, whether they seek out quiet natural environments along the mangrove waterways and in the wilderness of the Everglades or vibrant international culture in Miami. Yet this paradise is threatened by a number of forces – changing climate, rising sea level, and too many people, to name a few. Florida’s past is filled with stories of dramatic change and resiliency, if we look at the geologic record. It also hints at the role of climate alone, in the absence of significant sea level change, in shaping the mangrove coast. Using our knowledge of present-day processes, such as impacts of storms on the mangroves, combined with our interpretation of the past geologic record, is the best way to anticipate future changes. The question is, have humans altered this landscape so much that the species and habitats have lost their natural resiliency, and if they have, what will happen to the people and the unique environments of south Florida?

14. Chapter 13. Pictures from Space and Feet in the Mud: Understanding the Value of the World’s Changing Mangrove Forests

    David Lagomasino

    Abstract

    Mangrove forests line the coast of low-lying tropical shores. These habitats provide many types of ecosystem services that help protect and sustain communities around the world. Many of these locations are extremely difficult to get to, but we can use pictures taken from satellites in space to help us see where our coasts are changing, even in the most remote places. Using a combination of satellite imagery and ground information we can make regional and global estimates of the health and the structure of mangrove forests around the world. However, to make sure these estimates are accurate we need to visit these locations and make measurements on the ground. Our visits to these sites, with help from our in-country partners at universities and government agencies, can be difficult, fun, and enlightening all at the same time. We may have different objectives, but we all have the same goal, to sustain our coasts and the natural habitats within.

15. Chapter 14. What Is Happening to the World’s Coral Reefs?

    Pamela Hallock

    Abstract

    Coral reefs are in decline worldwide. Rising atmospheric CO₂ concentrations, which are causing ocean acidification and warming oceans, are clearly major threats to the future of coral reefs, but certainly not the only threats. Indeed, the range of threats increases with ever-increasing human populations. The consequences of local and regional activities are vast, including the ever-expanding impacts of environmental pollutants, coastal development, land-use in the watersheds, and even desertification in distant places that result in dust and smoke plumes that cross oceans and carry microbes. If a diversity of coral species and other reef-dwelling organisms is to persist and thrive in warming seas, humans must truly “think globally and act locally” to mitigate the compounding environmental damage that we continue to cause; the consequences of which are amplified by natural events such as major storms, volcanic eruptions, and earthquakes.

16. Chapter 15. The Water, the Coast, the Future

    Joy Moses-Hall

    Abstract

    The trouble with water on Earth is that it doesn’t stay put. At any one instant a droplet may be in the sky, in the ocean, frozen in a glacier, or in and among the lands. That dynamic system is reviewed in this essay, following droplets and following the accumulation of droplets that pins the totality of the waters, measured as sea level, at times and places throughout Earth’s history, through the lenses of our researchers. The message is that the Earth’s methods and responses follow the laws of science and geology, and we can expect Earth to follow the same methods and responses as the climate warms in coming years. Sea level imprints tell us what happened before, and what happens now will determine the sea level imprints of the future.

17. Chapter 16. Afterword: The Power of the Ocean

    Stephen J. Culver

    Abstract

    As a graduate student in coastal geology, one does not expect to strike gas. This happened to the author in 1974 and the geologically unrelated aftermath led to an unforgettable demonstration of the power of the ocean and how this power can affect our coasts.