of climate change. Enjoy the challenge and the reward of working with scientific data and results!
Kristen St. John, Mark Leckie, Kate Pound, Megan Jones, and Larry Krissek
April 2021
About the Companion Website
This book is accompanied by a website, with resources for Instructors and Students.
www.wiley.com/go/stjohn/climatehistory2
The Instructor resources include:
Instructor Guides for each chapter
Figures and tables from the book
Completed versions of student Excel files
The Student resources include:
Chapter‐specific resources
Two supplementary chapters from previous edition
Chapter 1 Introduction to Paleoclimate Records
FIGURE 1.1. Cross sections (a view perpendicular to growth or accumulation) of (a) a tree, (b) a cave deposit (speleothem), (c) several tens of meters of glacial ice, (d) a coral, and (e) a sedimentary sequence.
Source: Photo credits: tree ring – http://www‐saps.plantsci.cam.ac.uk/treerings/index.htm; cave formation – Courtesy of John Haynes. Inset figure: speleothem cross section – Photo from ANSTO; Quelccaya Ice Cap – Lonnie Thompson, Ohio State University; X‐ray of a Porites coral skeleton (upper) and shown in UV light (lower) – Lough, 2010, http://wires.wiley.com/WileyCDA/WiresArticle/wisId‐WCC39.html; Santa Maria Basin lake sediments, Argentina – http://tocsy.agnld.uni‐potsdam.de/ex_correlation.php.
SUMMARY
This chapter serves as an introduction to paleoclimate records. In Part 1.1, you will compare and contrast the temporal and spatial scope of five major paleoclimate archives: tree rings, speleothems, glacial ice, lake and marine sediments, and sedimentary rocks. In Part 1.2, you will consider the challenges and strategies for obtaining cores from terrestrial and marine settings. You will also consider issues of sampling, reproducibility, resolution, and cost, which are common issues for all paleoclimate archive research. In Part 1.3, you will read about the 780 000 yr‐long. Owens Lake core record, and create a summary figure to synthesize the paleoclimatic data and interpretations.
Learning Objectives
After completing this chapter, you should be able to:
1 Compare and contrast tree ring, speleothem, glacial ice, lake sediment, marine sediment, and sedimentary rock paleoclimate archives.
2 Provide a rationale for which archive(s) would be best suited for different spatial and temporal constraints and scientific objectives.
3 Identify the challenges and strategies for obtaining cores from terrestrial and marine settings.
4 Explain why unique sample identification is essential and how that is achieved, as well as the importance of reproducibility, and how it can be achieved.
5 Calculate accumulation rates and explain how sample resolution is affected by accumulation rates.
6 Describe the 780 000 yr‐long. Owens Lake sedimentary record, including the methods of age determination, the types of data collected, and a time‐line interpretation made of the paleoclimatic and environmental changes it has recorded (both naturally caused and human‐influenced). This serves as a case study of the science that can be derived from a paleoclimatic archive.
Part 1.1. Archives and Proxies
1 Think about how we know about past events in human history (e.g. the expansion of the Roman Empire, or the American Revolution). What types of records document those events?
2 Now think about Earth's history, specifically the past environmental or climatic conditions at times before recorded human history. What records might there be of such conditions? Make a list of your ideas.
3 Figure 1.1 shows an assemblage of five major types of natural archives of Earth's environmental and climatic history. What common feature(s) do each of these paleoclimate archives share?The photographs in Figure 1.1 comprise an assemblage of five major types of natural records, or archives, of Earth's environmental and climatic history. Just like a diary or other historical document, the layers in these natural archives contain indirect evidence (i.e. proxies) about past conditions and events, recorded in sequential order. The evidence is specific to a certain time period and may be general or very detailed, depending on the rate at which that information was recorded. The faster the rate at which the recorder grew (trees and corals), accumulated (snow and ice), or was deposited (sedimentary sequences), the more detailed the record is, and the higher its resolution. For example, a record in which an annual signal can be observed has a very high resolution. In contrast, if the finest observable details are on the order of a million years, then that record would have a low resolution.The usefulness of a record is also affected by how regularly information was recorded. If information was recorded continuously the record would be more complete than if events were recorded only occasionally.
4 Consider again each of the archives in Figure 1.1. Mark an “X” on each figure to indicate the oldest part of the record. Explain your reasoning here:FIGURE 1.2. Terrestrial and marine depositional environments, and example settings (lettered red boxes) of paleoclimate archives. Letters correspond to archives in Figure 1.1. A = tree ring record in a forest, B = cave system containing speleothems, C = glacial ice, D = coral record in reef setting, E1 = sedimentary sequence in a mountainside outcrop, E2 = sedimentary sequence in a lake bed,
