Paleo Slide Set: Coral Paleoclimatology
Extracting core with hydraulic drill on a Porites lobata colony, Clipperton Atoll

The scientists have found an ideal candidate. Armed with a hydraulic drill connected 
to a compressor on ship, they begin to take their core. The most important part of the 
drilling process is trying to get a core that follows the coral's plane of maximum growth. 
Think of the coral's structure as being very similar to an onion sliced in half, 
with a new ring added each year. If you wanted to drill into an onion to sample 
as many rings as possible, you would core from the surface directly towards the center. 
This is exactly how scientists go about getting as long a sample as possible from each coral.

Photo Credits:
Maris Kazmers
SharkSong Photography, Okemos, Michigan