Lab 1: Global warming during the Paleocene-Eocene Thermal Maximum (PETM)
Download this lab worksheet as a Word document: Lab 1: PETM (Please download required files below.)
In this lab, we explore the magnitude of the warming that took place during the PETM based on proxy data. We compare PETM temperatures with current temperatures as well as warming predicted for the year 2100. We will look at Mg/Ca, oxygen isotope, and TEX-86 proxy temperatures from a number of cores of marine PETM sediments drilled in the oceans and on land, as well as margin analysis of leaves from land sections, to determine the temperature change. If you have not read the relevant material on proxies and the PETM in this module, please go back and do this before you begin the lab.
Note: The data for this lab are provided in Google Earth files. The goals of this lab are:
- To compare the magnitude and rate of warming at the PETM with that of today;
- To get comfortable with Google Earth software, especially turning maps on and off.
If you have not worked through the Google Earth Tutorial in the Orientation, you must do so now.
Files to Download
Get used to manipulating these files in Google Earth. This short video shows you the basics of how you will need to do this for the lab (and it will be critical for future labs too):
Hi students. I'm going to give you a quick tutorial as to how to open these Google Earth files for the PETM lab. And then I'll show you how to turn them on and off in Google Earth and to move around a little bit. This is going to be critical for doing the lab in module one. Okay, so the first thing you need to do is go to the lab and I'm going to show you how to download a file. You just click on that file, like this, and then it'll open it directly in Google Earth Pro. You can see that. So I go "OK" and now it's opening my site locations with the site information. I'm gonna move the location here a little bit so that we're centered in the middle there. And let's say I want to open the Tanzania file to get the data out of it. I'm gonna click on that placemark, like that, and then I can read the data right off there. Oxygen 30.5 degrees centigrade pre-event; oxygen 41.9 degrees centigrade PETM. So you can then just type those numbers right into your spreadsheet. When I moved to another location, I'm gonna rotate it around, let's pick 527 site. And I click on that again, pre-event Magnesium calcium, PETM magnesium calcium, just put those right into your spreadsheet. It's really easy. Okay, so notice that my PETM data files are over here in my places. Right there actually in my temporary places for now. When I close Google Earth, it will ask me if I want to save them. So you can turn this on and off just by clicking, like this, bingo off they go. Bingo, back they come. Alright, and then here are the other files that I've actually pre-loaded. My paleogeography, my future climate, and my current sea surface temperatures, paleogeography current temperatures, future temperatures. So if I want to turn on my paleogeography, I just go to click, and on it comes. You can see the locations of the continents, there we're a little bit different. I want to turn it off, BAM, off it goes. I want to turn on my future temperature file, there it is. This is for one of the climate reconstructions for the future. It's a bit blurry but you can still read the numbers. You can see 2.4, .8. These are temperature changes that you'll be able to compare with the PETM warming, which was part of the last part of this lab. And then current sea surface temperatures, BAM, here it goes. There are my current sea surface temperatures and you have the scale at the bottom. So once again, you just need to make sure, as you go through this lab, that you're comfortable turning on and off these different layers because you'll need some of them on and some of them off at individual times, as is explained to you the instructions. So that's a quick go over as how to do the main functions that you'll need for module one lab. And please let Robert and me know if you have any questions and I will talk to you guys later on. All right, now I need to turn this off, and have a good day everybody.
Load the PETM Data.kmz file into Google Earth. The map shows continental positions and the extent of the ocean during the PETM. The red markers show the site positions that you will use for this lab. If you click on them you will get several pieces of information: (1) the proxy used to determine temperature; (2) the temperature just before the PETM (pre-event) and (3) the PETM temperature. I recommend you make a table similar to the example below, that shows all of the data, as well as your calculated temperature change.
|Site Positions||Proxy||Pre-event Temperature||PETM Temperature||Temperature Change|
Next, practice turning on the modern sea surface temperature (SST) map in the Modern SST.kmz file as well as the map that shows SST projections for 2100 in the Projected Temperature.kmz file (this file shows temperature anomalies, meaning increases in temperatures in degrees C). Please note that you can only have one of the Modern and Projected Temperature files turned on at any time, but you can have the PETM data kmz file turned on with them to compare the PETM temperatures with those of today and those projected for 2100.
Note that since the continents have moved a long way in 55 million years since the PETM, there are places in the PETM ocean which now lie in the position of the modern continents and thus don’t have equivalent modern temperatures (you will see some PETM sites in the dark blue area of the modern continents).
After you have made the table from the data that you collected and feel comfortable comparing the data with temperatures read from the temperature kmz maps, please answer the practice questions below. Once you feel good about your answers, go to Lab 1 in Module 1. There will be two labs available to you, Lab 1 Submission (Practice) and Lab 1 Submission (Graded). You will have a chance to answer practice questions and get the correct answers before taking the Lab 1 Graded questions for credit. Please make sure you fully understand the practice questions before you start the graded questions for credit. You may want to review some of the content in Module 1 to help prepare. Keep in mind that you will only get one chance to complete the graded labs.
- What is the temperature increase at Bass River during the PETM (give your answer in degrees centigrade)?
- Which oceanic site (i.e., only site with numbers located in the ocean basins) has the smallest temperature change?
Now turn on the Modern temperature map and answer the following questions:
- Compared to modern temperatures, is the location of Site 277 warmer or colder during the PETM?
Which oceanic site (i.e., only sites with numbers located in the ocean basins) has the smallest temperature difference between PETM and modern?
First, turn OFF the Modern temperature map. Next, turn ON the Projected 2100 map and answer the following questions.
Is the most significant warming in the projection at high latitudes (meaning above 60 degrees latitude North and South of the equator)? Yes or No
Comparing this to the PETM where there is no general pattern of warming with latitude, does the 2100 projection have a latitudinal pattern? Yes or No