But climate? We look to patterns of wind, temperature and precipitation. You can’t use a compass to tell you if it’s going to rain, but scientists have known for many years that climate and the Earth’s magnetic field move in similar fashion. They don’t understand if they are related and, if so, why.

The JOIDES Resolution in port at Ponta Delgada, Azores. IODP Expedition 339, Mediterranean Outflow. (Photo: John Beck, IODP/TAMU)

Stranger yet is where Chuang Xuan, a postdoctoral scientist at Oregon State University, is looking for clues to solve this mystery: the bottom of the Atlantic Ocean. Xuan has joined an expedition on the research ship JOIDES Resolution to drill deep into the seafloor where the Mediterranean Sea flows into the Atlantic. It is there, he says, that thick sediments deposited by the Mediterranean’s outflow may have preserved variations in climate along with the magnetic history of the planet.

The expedition is part of the Integrated Ocean Drilling Program (IODP), an international research program in which OSU scientists have played a leading role.

According to Xuan, the combination of high sediment accumulation rates and the type of sediment may yield excellent paleomagnetic records — good enough to record small geomagnetic changes that scientists call “excursions” — as well as high-quality paleoclimate data from the same sediment sequences. He plans to study correlations between the two types of records to see whether and how geomagnetic field variation and climate change might be connected.

Chuang Xuan (Paleomagnetist, Oregon State University) and Carl Richter (Paleomagnetist, University of Louisiana) discuss the results of their testing. Expedition 339, Mediterranean Outflow, of the Integrated Ocean Drilling Program. (Photo: John Beck, IODP/TAMU)

A member of OSU’s Paleo-and-Environmental Magnetism Laboratory in the College of Earth, Ocean, and Atmospheric Sciences, Xuan studies the process that causes deep-sea sediments to be magnetized. By deciphering past variations in Earth’s magnetic field, he works to understand the causes and consequences of geomagnetic change. He uses magnetic records from Arctic sediments for paleoenvironmental and stratigraphic applications. He also develops software to process large volumes of paleomagnetic data on sediment cores.

Xuan received his Ph.D. in geology from the University of Florida in 2010. He earned his master’s in applied mathematics in 2005 from China University of Geosciences, Wuhan, where he also received his bachelor’s in geology in 2002.

See weekly trip reports, photos and other information about the expedition.

About IODP

The Integrated Ocean Drilling Program (IODP) is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor. The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP (USIO). Together, Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University, and the Consortium for Ocean Leadership comprise the USIO.  IODP is supported by two lead agencies: the U.S. National Science Foundation (NSF) and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Additional program support comes from the European Consortium for Ocean Research Drilling (ECORD), the Australian-New Zealand IODP Consortium (ANZIC), India’s Ministry of Earth Sciences, the People’s Republic of China (Ministry of Science and Technology), and the Korea Institute of Geoscience and Mineral Resources.

In 2008, I participated in one of the few scientific expeditions aimed at characterizing the abundance of plastic debris and the associated impacts of plastic on microbial communities. That expedition was part of research funded by the National Science Foundation through C-MORE, the Center for Microbial Oceanography: Research and Education.

Plastic “nurdles,” a pre-production material for manufacturing plants, are a common cargo in merchant vessels and a significant component of ocean pollution. OSU oceanographer Charles Miller recovered these plastic bits (about 3 millimeters across, less than half the size of a pencil eraser) from the North Pacific gyre in 1971. (Photo: David Reinert, COAS; photoillustration, Teresa Hall)

Standing on the bow of a research ship, floating in the heart of the alleged garbage patch, my colleagues and I looked out onto a calm, apparently pristine blue ocean. By towing a mesh net through these waters and deploying instruments capable of measuring particle size and abundance, it became clear that the sea around us actually contained few, very small pieces of plastic. If you were to line up 1,000 1-liter Nalgene™ bottles filled with ocean water from this location, one to five of them would contain a single piece of plastic roughly the size of a worn-down pencil eraser. In comparison, plankton (millions to billions of organisms per milliliter) outnumber and outweigh plastic by a considerable measure.

The amount of plastic out there isn’t inconsequential, but using the highest concentrations ever reported by scientists, the plastic debris floating in the surface waters of the North Pacific could be rounded up to produce a patch that is a small fraction of the state of Texas, not twice the size. This is not to say that the issue of plastic in the ocean should be dismissed; rather, the problem is more complex and enigmatic.

One of the longest records of ocean plastic comes from the western North Atlantic. Compiling a 22-year survey of plastic debris, researchers reported concentrations very similar to what we found in the Pacific, but there was a catch. The amount of plastic in the North Atlantic has not increased since the mid-1980s, despite a surge in plastic production over the same period. This unexpected conclusion has led to a lot of speculation: Are we doing a better job of preventing plastics from getting into the ocean? Is more plastic sinking out of the surface waters? Is plastic being more efficiently broken down? At present, we just don’t know.

New research findings may point to one part of the answer: microbes! Not only is plastic prime real estate for microbes, but they may actively degrade it. This interesting finding may partially explain the mystery of “missing plastic” in the Atlantic.

If there is a take-home message, it’s that plastic clearly does not belong in the ocean. The practical solution is to reduce the input of plastic into our oceans in the first place. There is no need to exaggerate the problem to Texas-sized proportions.

Co-chief scientist Anthony Koppers (left, Oregon State University, USA), expedition staff scientist Jorg Geldmacher (middle, Texas A&M University, USA), and co-chief scientist Toshitsugu Yamazaki (right, Geological Society of Japan at the National Institute of Advanced Industrial Science and Technology in Japan) led the IODP Louisville Seamount Trail expedition from December 2010 to February 2011. (Credit IODP-USIO)

Talk about taking things in stride. Three scientists stand at a ship’s railing, arms on each others’ shoulders, sun on their faces and a calm blue sea behind them. They look like tourists on a cruise. Nothing in their calm expressions suggests that they have just pulled half a mile of rock out of the Earth. Or that the rock will help them to answer questions about  how the planet’s tectonic plates move or about how microbes mingle with heat, water and pressure deep underground.

Oregon State University Professor Anthony Koppers and Toshitsugu Yamazaki of the Geological Society of Japan were co-leaders of the latest cruise conducted under the auspices of the International Ocean Drilling Program (IODP). Their target:  the Louisville Seamount Trail — a 2,600-mile-long line of underwater mountains in the South Pacific — where they hoped to learn more about the geophysical processes that produce such features as the Hawaiian Islands or the stretch of ancient volcanoes between the Oregon Cascades and Yellowstone National Park.

Koppers co-edited a special March 2010 issue of the journal Oceanography focusing on seamount science.

According to an IODP news release, the scientific team on the research vessel, JOIDES Resolution, returned to Auckland, New Zealand on February 15 with 806 meters of rock pulled from the seamounts. “During this expedition, we sampled many ancient individual lava flows and a fossilized algal reef.  These samples will be used to study the construction and evolution of the individual Louisville volcanoes,” said Koppers.

Night view of the JOIDES Resolution docked in Auckland, New Zealand before its departure on 13 December 2010. (Credit D. Buchs, Australian National University)

Added Yamazaki: “The sample recovery during this expedition was truly exceptional. I believe we broke the recovery record for drilling igneous rock with a rotary core barrel.” A rotary core barrel is a type of drilling tool used for penetrating hard rocks.

The samples were recovered from six sites at five seamounts varying in age from 50 to 80 million years old.

Linear trails of volcanoes found in the middle of tectonic plates, such as the Hawaii-Emperor and Louisville Seamount Trails, are believed to form from a hotspot – a plume of hot material found deep within the Earth that supplies a steady stream of heated rock from depths as great as 2,900 km up to the surface. As the tectonic plate drifts over the hotspot, new volcanoes are formed – and old ones become extinct. Over time, a linear trail of these aging volcanoes is formed.

“Submarine volcanic trails like the Louisville Seamount Trail are unique because they record the direction and speed at which tectonic plates move,” explained Koppers.

Scientists use these volcanoes to study the motion of tectonic plates, comparing the ages of the volcanoes against their location over time to calculate the rate at which the plate moved over a hotspot. These calculations assume the hotspot stays in the same place over time.

Shipboard technicians help carry a core of rock recovered from ancient volcanoes in the Louisville Seamount Trail. (Credit IODP-USIO)

“The challenge,” said Koppers, “is that no one knows if hotspots are truly stationary – or if they somehow wander over time. If they wander, then our calculations of plate direction and speed need to be re-evaluated.”

“But even more importantly,” he continued, “the results of this expedition will give us a more accurate picture of the dynamic nature of the interior of the Earth on a planetary scale.”

Recent studies in Hawaii have shown that the Hawaii hotspot may have moved as much as 15° latitude (about 1,600 kilometers or 1,000 miles) over a period of 30 million years.

“We want to know if the Louisville hotspot moved at the same time and in the same direction as the Hawaiian hotspot – our models suggest that it’s the opposite, but we won’t really know until we analyze the samples from this expedition,” explained Yamazaki.

In addition to the volcanic rock, scientists on this expedition also recovered sedimentary rocks that preserve shells and an ancient algal reef – typical of living conditions in a very shallow marine environment. These ancient materials show that the Louisville seamounts were once an archipelago of volcanic islands.

According to Koppers, “we were really surprised to find only a thin layer of sediments on the tops of the seamounts and only very few indications for the eruption of lava flows above sea level. It seems that the volcanoes have only been at or above the surface of the ocean for a short amount of time – we weren’t expecting this.”

Researchers hailing from all corners of the globe work together to take small samples from the Louisville Seamount Trail cores. These samples will be analyzed to determine the age, composition, and physical properties of the rocks. (Credit IODP-USIO)

The IODP Louisville Seamount Trail Expedition wasn’t solely focused on geology. More than 60 samples from five seamounts were collected for microbiology research, making the Louisville samples the largest collection of volcanic basement rock ever collected for microbiology research during forty years of scientific ocean drilling expeditions.

Exploration of microbial communities within the seafloor, known as the “subseafloor biosphere” is a rapidly developing field of research. Using the Louisville samples, microbiologists will study both living and relict microbial residents within the old sub-seafloor volcanic rocks from Louisville. They will examine population differences in the volcanic rock and overlying sediments and different kinds of lava flows. They will also look for population patterns relative to depth in the seafloor and between seamounts of varying ages.

Over the coming year, samples recovered during the IODP Louisville Seamount Trail expedition will be analyzed to determine their age, composition, and magnetic properties. Like a puzzle, this information will be pieced together to create a story of the eruption history of the Louisville volcanoes, which will be compared to that of the Hawaiian volcanoes to determine whether or not hotspots remain stationary over time.

About IODP

The Integrated Ocean Drilling Program (IODP) is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor. The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP (USIO). Together, Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University, and the Consortium for Ocean Leadership comprise the USIO.  IODP is supported by two lead agencies: the U.S. National Science Foundation (NSF) and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Additional program support comes from the European Consortium for Ocean Research Drilling (ECORD), the Australian-New Zealand IODP Consortium (ANZIC), India’s Ministry of Earth Sciences, the People’s Republic of China (Ministry of Science and Technology), and the Korea Institute of Geoscience and Mineral Resources.

Learn more about the IODP Louisville Seamount Trail Expedition.

Watch videos produced during the expedition.

Learn about the JOIDES Resolution.

Angel White photographed this organism during a recent cruise to study Trichodesmium, a microbe that can thrive on nitrogen from the atmosphere.

The two Oregon State University oceanographers are on the R/V Melville in the South Pacific between Chile and Easter Island. To scientists, the voyage is known by the acronym BiG RAPA, which stands for Biogeochemical Gradients: Role in Arranging Planktonic Assemblages. It is sponsored by the Center for Microbial Oceanography: Research and Education (C-MORE), at the University of Hawai’i at Manoa. Other scientists on-board are from Chile, Hawaii, UC-Santa Cruz, MIT and Woods Hole. C-MORE is a National Science Foundation-funded Science and Technology Center.

Faculty members in OSU’s College of Oceanic and Atmospheric Sciences, Letelier and White are investigating plankton that carry out photosynthesis, and by so doing, give us oxygen to breathe, fish to eat and ocean wonders from colorful squid to the largest mammals on the planet. Trouble is, we don’t really know how this medley of microbes works. Those that photosynthesize — the plants known as phytoplankton — have an appetite for carbon, nitrogen, phosphorus and iron, the building blocks of life. But how much of those nutrients do they need? And what happens to those elements after the plants are eaten or decomposed? How does this community change as temperature and chemistry shift along a gradient from the well-fed, nutrient-rich waters off Chile to the almost desert-like conditions of the open ocean? What will happen as ocean waters absorb increasing amounts of carbon-dioxide and become more acidic?

The answers are critical to our understanding of the oceans, not to mention our future. Microbes account for most of the biomass in the seas, far outstripping fish and marine mammals. Moreover, recent research reports suggest that as the oceans warm, phytoplankton populations will decline. In reviewing more than a century of data, researchers at Dalhousie University in Nova Scotia reported last summer that plankton have been declining about 1 percent per year on a global basis (Boyce, et al, “Global phytoplankton decline over the past century,” Nature, 2010).

Letelier and White are quick to note that at a C-MORE research site north of Hawaii, plankton production has been increasing over the last two decades. Some types, especially those that sip nitrogen from the air, do quite well in waters with additional carbon. Scientists on the BiG RAPA cruise are conducting experiments to see how CO2 concentrations affect phytoplankton behavior. The expedition, which began on Nov. 14 in Chile, is scheduled to conclude on Dec. 14 at Easter Island. See videos from the cruise produced by C-MORE.