Paleo Slide Set: Coral Paleoclimatology:Natural Record of Climate change for High School Student
Extracting core with hydraulic drill on a Porites lobata colony, Clipperton Atoll.

While drilling does kill a few polyps living on the core surface, it does not damage the colony as a whole. 
In fact, polyps often grow over the drilling holes within a couple of years. As we discussed earlier, only 
the surface of the colony is alive, the rest is the calcium carbonate skeleton deposited by the polyps. 
When a polyp grows and leaves the skeleton behind, the chemistry of that portion of skeleton is locked in. 
In other words, every time a piece of skeleton is created, an indelible record of the conditions under which 
it was created are contained within it. Some colonies live as long as 800 years! It is this ancient record 
that paleoclimatologists are trying to unlock by drilling long cores into the coral skeleton.

Once the drill reaches the center of the coral, scientists carefully extract the core pieces, label them and 
box them up for safe shipment home. Back in the laboratory, the excitement of the field work will be followed 
by new discoveries and new insights into our planet's past. Coral paleoclimatologists travel around the world 
to find coral in order to compare the chemistry and growth of different areas. Most spend a few weeks a year 
doing their field work. The rest of the year, paleoclimatologists analyze samples like this core segment that 
they have gathered in the field, teach courses to college students and write articles and books about their research. 

Photo Credits:
Maris Kazmers 
SharkSong Photography, Okemos, Michigan