Past 48 hours of sampling….

February 27, 2010

Julie and Carlie get muddy while taking 6" and 4" sub-cores from the box core

Our fearless leaders make decisions about where to take sediment cores and water samples

On the continental shelf of Brazil we were surprised to find fragments of coral reef in one of our multicore deployments

February 26th

For the past 2 days we have been following a transect from deep ocean sites, westward toward the continental shelf of Brazil to look at the transport of fluvial sediments coming from the Amazon River. Our shallowest sampling site was in just 35 meters of water, and we were < 100 miles from the coast of Brazil. The water changed from the crystal clear blue color of the open ocean, to a muddy green/brown, indicating that we were close to the Amazon River outflow.

Enrique and Claudia deploy the in situ water pumps to filter particulates from seawater

The winch lowers the rosette, which has 24 niskin bottles, over the starboard side of the ship

Laura collects water from a niskin bottle that was deployed just above the seafloor

At each site we deployed the rosette (equipped with instrumentation that measures water parameters like salinity and temperature) to collect seawater samples at different depths in the water column. Laura and Kara filter the seawater (a process that takes 4 hours per deployment) to collect particulate matter, which they will analyze when we return to USF. We are also collecting box cores and multicores to analyze the most recently deposited sediments. Although a lot of our sampling took place in the wee hours of the morning, you can see that we weren’t shy about getting covered in mud. At one of the shallow sites, we were expecting soft sediment, but our cores came up with pieces of coral, brittle stars, and sponges, indicating that we had hit a reef.

Julie smooths the surface of the gravity core sediments to look for sedimentary structures

Julie and Claudia have fun with their proper safety attire on deck!

The piston core

February 25, 2010

The coring crew of the RV Knorr attaching the core head to the barrel

The orange barrel of the long core stowed on the starboard side of the ship. The 3 cranes are used to lift it over the side into the water.

2/25/10

We have been coring for a few days now, although the days start to blur together when instruments are being deployed nearly 24 hours a day. We were all fascinated to watch the jumbo piston core. The core barrel is over half the size of the Knorr.  To quote the Knorr WHOI website:

“In 2006, the ship was refitted to support a new ‘long-coring’ system that can extract 60-meter (150-foot) plugs of ancient sediment from the seafloor. Weighing nearly 11 metric tons (25,000 pounds), the new piston-coring system is the longest in the U.S. research fleet (twice as long as existing systems).”

In order to deploy this massive piece of equipment, the core is lowered from its horizontal position on the deck and rotated to vertical underwater. It is then attached to the rear A-frame, and lowered below the boat. The rear deck of the boat has literally been sliced in half and reinforced to allow the core to hang on a pulley system under the deck.

Once brought back on board, the barrels inside the long core are removed and stored on 1.5m long segments.

First day of Coring

February 24, 2010

2/23/10

The crew and scientists of the Knorr have spent  four long days in transit. It was a good time to catch up on sleep and prepare for the monumental tasks ahead. During this time, we also unpacked the 30 crates and boxes of scientific equipment that we loaded onto the Knorr while it was conveniently docked in Tampa in January. All of our gear was stored two floors below main deck in the engine room.

Today we arrived on our first sampling location. Deploying the numerous instruments and coring devices is a very time consuming procedure. It takes over an hour for a coring device to be lowered to the ocean floor at 1700 m depth.  At a single site, we will utilize a box core, multi-core, gravity core, CTD rosette (for water samples and water chemistry), and a jumbo piston core. This requires at least 15 hours of labor to complete one location.

The first coring device utilized today was the box core. This apparatus is lowered to the bottom of the sea where is sinks into the ground. A trigger snaps the box shut, taking a bite out of the sediment, which is then pulled to the surface. We took several subcores out of the box core for further analysis. It’s a messy job, but once the cores were cleaned off, they revealed distinct horizon lines with darker sediment. The sediment is also full of forams. These carbonate producing phytoplankton settle to the bottom of the ocean when they die. Through analysis of their shells, we can determine what the temperature of the ocean was in the past.

Destination Amazon!

February 19, 2010

Lead researcher David Hollander, doctoral student Julie Richie and their colleagues load gear on the R/V Knorr

 The scientific crew of the R/V Knorr set sail from Bridgetown, Barbados at 0900 on Friday, February 19, 2010.  Our destination is the Amazon River basin where a group of researchers from the University of South Florida’s College of Marine Science are headed in search of answers to some of the great questions about climate change.   

For USF researcher David Hollander and a six of his colleagues from the College of Marine Science, the secret to some 60,000 years of the Earth’s climate history is buried in the deep mud below the Amazon River basin off the coast of Brazil. And for the next 26 days, our team will begin the process of revealing that long-buried history up – one long, thick cylinder of sediment at a time.   

Joining Hollander are students from USF’s College of Marine Science: Julie Richey, Carlie Williams, Kara Radabaugh, Enrique Montes and Laura Lorenzoni.   

Also on the cruise is Paul Baker of Duke University – you can follow his account of our journey on his blog, AmazonPaleo.  

So why would scientists need to know about what happened in the Amazon tens of thousands of years ago? Because without an accurate and complete historical record of how the planet’s climate has behaved in the past, it makes it very difficult to truly understand what’s happening today.   

Hollander – who has traveled the world extracting sediment cores which give up that long-hidden history – believes that understanding climate change in the Amazon is crucial to today’s environmental challenges.   

David Hollander has traveled the world to document the history of climate change

 The regions high levels of rainfall, diverse plant and animal life and massive stores of carbon make it so crucial to the world’s climate that some scientists refer to the region as the world’s “lung.” The World Wildlife Fund describes the Amazon’s hydrological cycle as the key driver of global climate, thus making the climate sensitive to changes in the Amazon.   

USF is leading an international crew on this three-week mission. Their work is funded by the National Science Foundation.   

And how cool is this: The R/V Knorr is the vessel that discovered the wreckage of the RMS Titanic in 1985.   

At 279-feet long, the vessel from Woods  Hole Oceanographic Institute carries 49 people on its voyage.   

The R/V Knorr during its stay at Port of Tampa

In addition to the seven from USF, there is also a Dutch scientist, 5 scientists from Duke University, a Brazilian geologist and a Brazilian Navy Commander.   

We will be collecting sediment cores from 2 km under the ocean surface off the coast of Brazil – a protected area that has not been studied before.  Our goal is to use the long coring system on the R/V Knorr, which is capable of taking 150 foot-long plugs of sediment from the ocean floor, the longest continuous coring system in the U.S. fleet.    

Our journey has just begun, so stay tuned for updates about our exciting discoveries at sea.   

To keep track of the ship, visit “Where is Knorr Now?”  from Woods Hole Oceanographic Institute.

The USF contingent on the R/V Knorr