To Boldly Go Where Three Other Expeditions Have Gone Before

The JOIDES Resolution is currently drilling in a hole that has already been drilled during three previous expeditions. The JR is not back again because we are running out of places to drill or because one of the scientists on the last expedition lost his keys in the hole, but because this expedition is breaking new ground (literally).
 
Most of the JR’s expeditions rarely drill holes deeper than 100 meters (about 328 feet). We have learned a great deal about the ocean floor and the Earth from the cores drilled from these holes. The ocean crust is much thicker than 100 meters, though. It averages about 7,000 meters (about 22,965 feet deep!). By drilling deeper, we can learn even more about the ocean crust. Because it was drilled three prior times, the Superfast hole is already over 1,500 meters (4,900 feet) deep, and by the end of this expedition, should be much deeper.
                                                  
                                                                                        Image from Science Buzz website
 
On this expedition, the JR will continue to bring up cores of rock never before seen by any human being (or any raccoon, for that matter). What will we learn from this expedition?
  • What ocean crust is like when it was spread superfast.
  • How much ocean crust is made by lava and how much is made by magma.
  • What kind of rock types do you find as you drill closer to the Moho.
  • How does the lower ocean crust heat up and cool down.
 
Superfast spreading? Moho? To find out what these and many other terms mean and why this expedition rules, stay tuned to the JR junior blog.
 
Sincerely,

The Blogfish 

Comments

Gabbro

Why are you stopping at the gabbro? Is the gabbro down there harder than it is when you buy a sample or in our class room?
-gabbro
- I also asked the temperature and water temperature questions

We are just drilling into

We are just drilling into gabbro because that is all we have time to do on this expedition. The gabbro is a very thick part of the crust and we will only be able to scratch the surface of it on this expedition, because drilling and bringing up cores from this deep takes a long time. Hopefully, future expeditions will be able to drill much deeper.

Crust????????????

How Deep is the Earth Crust, were you are drilling

From, Aaron

PCDS

The Earth's crust is 6 kilometers thick

Aaron, the Earth's crust is 6 kilometers thick. You might want to take a look at our 4/24/11 blog post, "How Deep Can We Go?" (http://joidesresolution.org/node/1870), which includes a diagram of the basic layers of the Earth, including the crust.

Right now the hole we are

Right now the hole we are drilling is just over 1500 meters deep in the crust.

the moho

what is this moho and is it a rock or an area of the earth or is it the area your team is trying to drill to, also why does your team usually only drill 100 meters what info could you find at the depth in the earth-BERNARD

The Moho is the boundary

The Moho is the boundary between the crust and the mantle. We usually only drill less than 100 meters because it takes a long time and is expensive to drill deep into the ocean floor. Most of the scientists can best find the answers to their research questions by drilling many holes in different places, rather than one deep hole. If money and time were not an object, though, most scientists would probably be happy to drill as deep as they could at each hole, because they could learn a lot more that way.

Layers of Earth

Hi People! I was wondering how you know when youv'e reached the layer you want to get to? Is there a camera on the end of the pole or drill?
-ELLEBOB!

Scientists can have an idea

Scientists can have an idea of what is down there by running seismic waves through the layers to see what they might be. Almost all of these expeditions are about discovery, though, so we do not know for sure what is in the layers until we drill into them and bring up the cores on the ship so the scientists can begin examining the rocks within them.

Rocks

Whats the difference between Gabbro and Layered Gabbro? -M.G.

A number of factors effect

A number of factors effect the form the gabbro takes. If it is basically just a big blob of rock it is referred to as gabbro. If the gabbro forms layers it is layered gabbro. Whether a gabbro forms in layers depends on factors such as the density of the magma and whether there is a ceiling of rock the magma cannot break through, such as the bottom of the ocean crust, where the magma cools and hardens in layers.

Gabbro

hi guys! i was wondering if you reached your goal of drilling to the Gabbro yet? if so have you gotten he information that you wished to gain?
thanks so much!
#1fan--chanel

The scientists are starting

The scientists are starting to examine the cores now, but we still hope to examine many more before the expedition ends.

Not yet, but they just

Not yet, but they just started drilling.

MOHO

hi! i was wondering what a MOHO was? is it a drill that can drill really deep? thanks so much!
#1fan--chanel

The Moho is the boundary

The Moho is the boundary between the crust and the mantle. I will be writing more about the Moho in a blogpost in just a couple weeks. - The Blogfish

MOJO?

hi! i was wondering what the MOJO was? thanks so much!!
#1fan--chanel

I think you mean Moho, and

I think you mean Moho, and you can find out what that is in my response above. Mojo is something Muddy Waters used to meet women. - the Blogfish

Is the Mojo superfast

Is the Mojo superfast spreading? If so, would it make it more difficult to drill down if it kept spreading?
CACTUS GAL(:

The seafloor we are drilling

The seafloor we are drilling in has spread superfast in the past, compared to other seafloor spreading areas, but it would look superslow to us (it's a rate of centimeters per year). I will be writing a blog about how fast is superfast next week. How the Moho changes is something that marine geologists have been wanting to learn for a long time, but so far no one has been able to drill that deep. I will be writing a blog about that soon as well. -the Blogfish

It sounds like MOJO would be

It sounds like MOJO would be super fast spreading.....can you keep going deeper down if it spreads too fast? Will it make a difference? Thanks:) -Iya A.

All the crust is spreading at

All the crust is spreading at about the speed your fingernails grow, including the Moho, so it will not affect drilling.

Crust

Hey! Are you guys digging into continental crust or oceanic crust? If you are digging into oceanic crust, have you reached the gabbro yet? If you are digging into continental crust, have you reached the granite yet? -Splash

We are drilling on oceanic

We are drilling on oceanic crust and should be the first research expedition to ever drill in gabbro.

We're trying to get to gabbro from the lower crust...

Actually, other scientific expeditions have drilled into gabbro before. It's the gabbro lying in the lower (deeper) layers of fast-spreading ocean crust that we haven't been able to drill into before. This kind of gabbro's not easy to get to, because it usually lies under 1000 to 2000 meters of really hard rocks that lie above it in the upper crust. In ocean crust that formed at slow spreading rates (in the Atlantic and Indian Oceans for example), where the crust is thicker, the gabbro's a lot easier to get to -- and in fact, other expeditions have already drilled and cored quite a bit of that gabbro (so scientists have lots of samples of that type of gabbro to study). What we're hoping to do on this expedition, is to be the first to drill into intact oceanic crust that formed superfast, and recover gabbro from the lower crust. That would make it the deepest type of rock ever taken from intact fast-spreading ocean crust.

Ages of Rocks

How do you, personally, find the ages of rocks? What device or observation helps you figure out how old the rock is? It is something to do with what it is made of?
-ELLEBOB

The scientists use

The scientists use radiometric dating. There are particles in rocks such as uranium and potassium that are radioactively decaying at a known rate that takes millions of years. Once the scientists are off the JR and back in their labs, they can use equipment to find these particles and measure how much the particles have decayed. Depending on how much the radioactive particles have decayed, the scientists can then determine how old the rock was when it first formed. You can learn more about radiometric dating here: http://en.wikipedia.org/wiki/Radioactive_dating

Drilling

How do you know when youv'e reached the layer you want to get to? Is there a camera or recorder on the drill?
-ELLEBOB

See the response to "Layers

See the response to "Layers of Earth" above.

gabbro

What is the difference between Gabbro and Layered Gabbro?-M.G.

See the response to the

See the response to the comment "Rocks" above.

Have you reached gabbro?

Hi! I am aware that Basalt is on the surface of the ocean lithosphere. However, Gabbro is below it. Have you reached either of these rocks while drilling yet.- JAMIE FROM COOKS SCIENCE

We've seen lots of basalt in

We've seen lots of basalt in this hole. We're hoping to drill gabbro soon.

Heat!

I am currently learning about the earths layers in science class. I would like to know how far you could go into the earths layers before the heat would become to intense for a human to withstand?-Jamie FROM COOKIES SCIENCE

It varies depending where you

It varies depending where you are, but on average the crust warms up about 25 degrees Celsius for every kilometer deep you go. So, to convert that into Fahrenheit, one kilometer deep would be about 120 degrees Fahrenheit. Two kilometers would be about 170 degrees Fahrenheit. Humans can have heat related health issues at temperatures above 100 degrees Fahrenheit.

drillin holes!

hi guys! i was wondering if you have achived your goal of reaching the Gabbro yet? if so what information have you gotten so far about whatever it was that you were looking for? and if you havn't reached it, what is the information that you are hoping to gain? thanks so much!
#1fan--chanel

We haven't reached gabbro

We haven't reached gabbro yet. This blog will tell you what we're hoping to learn from it: http://joidesresolution.org/node/1901

MOHO?

what does the MOHO mean? does it stand for something or does it mean something that i just dont know the name of! thanks so much
#1fan--chanel

See the response to the

See the response to the comment "Moho" above.

how deep?!

Hi crew of Joides Resolution! my name is chanel, and i was wondering how far deep you guys have drilled so far? i know it is very hot in the core of the earth, but is that what is keeping you from drilling that deep? or is it that man kind hasn't developed the technology yet? thanks so much!
#1fan--chanel

Read the response to the

Read the response to the comment "the moho" above.

I see that you are trying to

I see that you are trying to get to the Gabbro but why don't you want to go farther to the peridotite. Are you just looking for Gabbro samples?-Bain

Drilling the ocean floor

Drilling the ocean floor takes a long time and is very expensive. Scientists would love to drill to the peridotite, but it is not something anyone has had the time or money to do yet.

Question on Drilling!

Hello im R. Kothur
I was wondering if there was a specific reason why you never decided to drill down deeper to find more helpful information? Also what is MOHO and why is it in the layer of peridotite??? Have fun drilling!

The Moho is the boundary

The Moho is the boundary between the crust and the mantle. Drilling the ocean floor takes a long time and is very expensive. Scientists would love to drill deeper, but it is not something anyone has had the time or money to do yet.