Durring the Fall of 2005, Bryan Kennedy, Exhibit Developer at the Science Museum, answered museum visitors questions about drilling into the earth's crust under the ocean. Learn more about Bryan Kennedy's research.
Dude, how do drills get rock samples from the sea floor? And what kinds of things can you learn from the samples?
To get rock samples from the sea floor they use a long piece of steel pipe (thousands of feet) with a drill bit on the end.
The rig on the ship turns the drill bit and cuts a core sample to bring back to the surface. They only drill 1.5 meter sections at a time. These "drill-cores" are then pulled back up to the ship where the scientists can analyze them.
By looking closely at these samples we can find fossils and chemical signatures. One of the most important reasons to do this is to learn more about the history of our climate.
How do fossils and chemical signatures tell us about past climates? Can you give us an example?
Yes. Oxygen isotopes are one of the best examples. Oxygen comes in a couple forms. We call these isotopes. The two we need to worry about here are O-18 and O-16. Oxygen is found all over the earth but most importantly it is a real important part of water (remember H20). Well water also travels all over the planet through ocean currents, evaporation, melting of glaciers, rain, and many other ways. When the earth is warmer of colder these processes change. You either get more ice, or more rain, or more evaporation. All of these processes affect what kind of Oxygen (O-16 or O-18) we see more of in the rocks that form at that time.
So to make things real simple, we are able to study the different types of oxygen in the rocks we drill to understand whether it was warmer or colder millions of years ago. It's pretty complex but the thing to take away is that Oxygen is a marker of the earth's ancient climate.
What are the ecological effects of a big ship drilling into the ocean floor? Doesn't it mess up the ocean and the things that live there?
Perfect timing. I just learned the answer to this question last night. The JOIDES Resolution uses a riserless drilling rig. So when they drill down into the sea floor they don't really have any control of what material comes out of the hole.
On a more expensive ship, like the ones they use to look for oil they use a riser system. This means that anything that comes out of the hole can be captured and doesn't spill out into the ocean. This is especially important if the stuff coming out of the hole is oil or gas. After all this is what the oil companies want anyways.
But don't worry to much each of the planed drilling sites for the JOIDES Resolution are run through a committee including people who look at the environmental impact on this sort of drilling.
The drilling project will be finishing up a new ship built by their Japanese partners, called the Chikyu. IT should be completed in 2007.
Is the trip you're on just about teaching teachers, or is there an actual scientific mission?
During this trip there is not a scientific research mission. We are just on a transit. Which means we just really need to get the boat from one place to another.\r\n\r\nWe originally had planed to visit one of the old drilling sites to repair some equipment but the weather was far to strong and we had to abandon that attempt. \r\n\r\nAs soon as we get off though a new research leg is beginning. In that trip they will be drilling into one of the original drilling project holes. They are going to see if they can drill deeper into the crust than has ever been drilled before. \r\n\r\nI am going to try and meet some of the scientists doing this when I leave so that I can keep Science Buzz readers informed about their progress.
What's it like to live on the ship?
Most of the crew shares small four person rooms with two bunk beds. Two rooms share one bathroom, so you have to knock before you get in there.
In some ways it's great. All of our laundry is taken care of for us by the hotel staff. Yep, they call the part of the boat where everyone sleeps, the hotel! There are four meals a day with a wide variety. Although I have heard that on the longer trips the meals start involving lots of cabbage.
At the same time it is hard to get used to the motion of the sea, and you can get very sick. On the rough wavy nights it's hard to sleep because every 2 min. or so a huge wave might crash into the side of the boat making a huge clanging sound next to your head. But, you get used to it.
You have to be careful when you walk around the ship since everything is always moving. One second you could be throw up the stairs and then another you get thrown down. Gotta keep alert.
On clear nights you can see some of the most amazing sunsets you have ever seen. I can't get over the enormity of the ocean. It just goes on and on.
I also hear that everything gets better in warmer weather. As we head down to Mexico I think we are going to have a big BBQ out on the deck of the ship. That should be fun.
What's the coolest/most amazing/scariest/most beautiful/most interesting thing you've seen so far?
Well, the internet wasn't working for a while! Ack, no I am just kidding. The ship has a big hole in the middle so that we can drill down into the sea floor. On the ship they call this hole, the moon pool. On our roughest sea day it was scary/awesome to walk down this narrow hallway of the ship called "suicide alley" to look at the moon pool. Every time the ship would hit a big wave, the moon pool would explode with water like a geyser. Water was flowing everywhere and that part of the boat almost looked underwater. If you were in the wrong place you could easily get swept off into the sea.
Well I am a big science nerd so I have to admit that the coolest part of the ship is the lab stack. Imagine 4 high tech labs stacked on top of eachother and then welded to a boat so they can go anywhere in the world. Pretty cool.
The ocean is an indescribable beauty. I could simply stand on the deck for hours watching it go about its business.
Is everyone on the boat a geologist, or are other scientists along, too?
Well, everyone is focused on earth science in some way, but there are many other types of scientists aboard. Some are chemistry focused, some look only at magnetism, and that doesn't even cover the techs.
The techs are all the people who keep the ship running. They use the scientific process every day to calculate all kinds of things like the complex drilling process or figuring out how much fuel we need to buy so that we can get to Acapulco.
Hey Bryan, you seem really cool. I saw your picture on the boat website blog looking into the microscope and stuff - dude, what's that thing behind yer ear!? Much XO.
Lots of people around here have those little patches behind their ear. It is a little time released medicine sticker, that hopefully keeps me from getting sea-sick. The patch contains a drug called Scopolamine and it helps your brain ignore all the confusing signals from the inner ear that make you sea-sick.
Unfortunately, it also makes your mouth really dry and fogs up your head. So now that the seas have calmed down I am hoping to stop taking it.
What is on the bottom of the ocean?
There are many things living on the surface of the ocean floor. However, scientific ocean drilling is much more interested in learning what is going on below the surface. Drilling research has revealed that life is teaming under the ocean floor. For tens of meters below the surface you can find all kinds of interesting microscopic life forms.
What does knowing what the earth's climate was like millions of years ago mean for us today?
It allows us to be better stewards of our planet today. We have learned that climate in the earth's past has changed quite dramatically. Ocean drilling research shows that these changes can happen very quickly, sometimes over the course of only a few hundred years or less. That means that we need to pay very close attention to changes in our present day climate and what they may mean for our children.
Why are you drilling under the ocean?
Well, on land it's pretty easy to hike out to an outcrop where there are rocks exposed and use a hammer to knock off a chunk of rock. Then you can study the rock in the lab or under a microscope. But this only tells you part of the story. We also have to look at the rocks under the ocean. The easiest way to get to these rocks is by drilling down to the sea floor. It would be very hard for a submarine to dig deep under the seafloor for samples.
Why do you think this is a good idea?
Yes, I think this research is very important. It's expensive, difficult, and time consuming. But without this program our understanding of how our planet works would be very limited.
How long does it take to drill down to 27,000 feet?
It depends. The people who are in charge of drilling on the ship include core techs, roughnecks, and drillers. They each have different jobs and are all very skilled at what they do. So sometimes they can go very quickly, bringing new 1.5-meter sections of rock core up onto the ship every 20 minutes.
However, if they are drilling through very hard igneous rock (like granite) it can take much longer. But, the deepest they have ever been able to drill below the sea floor was 1,416 meters (4,714 ft.). If we we're able to drill 27,000 feet down we would punch through the earth's crust into the mantle.
What have you discovered on the sea floor?
Well, on this mission we weren't able to do much science. We had hoped to fix one of the instruments placed on the Juan de Fuca ridge but the weather was to rough. In the next mission the ship will be trying to drill deeper into the earth's crust than ever before. They hope to understand what the boundary between the crust and the mantle might look like.
Wondering if there are and if so what are the physiological differences of animals indigenous to the specific depth regions in the ocean? Do ocean inhabitants reside in specific depth regions and are they therefore adapted to those variants in pressure and temp? Are there any other variants aside from pressure and temps at differant depths?
That is a great question Mary Sue. While I have been on the boat we have been studying lots of microfossils. These are the hard parts (shells) of little tiny animals that live throughout the world's oceans. Over the past millions of years their bodies have fallen to the sea floor and been compacted into sedimentary rocks.
When we drill into the sea floor we can find their bodies and identify different types. Two are the biggest types help us understand how deep the water was because of something called the "carbonate compensation depth". This is a fancy term that means that in really deep waters it is hard to get microfossils with carbonate in their shells. The microfossil's shells tend to be made out of more silicon (they are siliceous).
By studying these different fossils we can determine patterns in the worlds oceans from millions of years ago. The ability to do this comes from the fact that certain creatures live at different depths, just like you said.
is it hard to become a scientist?
Well, there is a lot of work involved. But it is some of the most fun work that you will ever do. In my work as a scientist I had to practice my math, chemistry, and physics to really understand how the earth works.
But all of this work paid off because I got to travel all over the world to study some amazing places like Hawaii, the Galapagos, and the Pacific Ocean.
You don't have to be a super science brain either to become a scientist. I was always better at my English classes in high school. But once I got to college I saw how much fun it was to study geology. So I did lots of hard work to make up for the fact that math and chemistry didn't come easy. So I guess it can be hard work but it pays off for sure.
Science Buzz is supported by the National Science Foundation.
Copyright © Science Museum of Minnesota, 2004-2015, except where noted.