The students heard from marine scientists who are pulling up rocks from the seafloor, a process called dredging, to study the chemistry of that part of the Earth and to better understand why some faults creep along, while other faults experience seismic activity, like earthquakes. 

They learned about an autonomous underwater vehicle (AUV) called Sentry that Dan Lizarralde, from Woods Hole Oceanographic Institution, likened to a “school bus for sensing.” The AUV is equipped with sensors, sonar, wires, batteries and cameras that allow it to take pictures and make maps of the seafloor. This can help scientists like Warren and McEllistrem understand the Earth and what’s happening in the farthest reaches of the ocean. Sentry can stay at the bottom of the ocean for a full day before returning to the ship to recharge.

“Our goal is to get students excited about marine science and show them that scientific research is conducted in many ways. For example, no one [on the ship] is wearing lab coats, but we are wearing steel-toed boots,” said Warren, lead principal investigator for the expedition.

It is just one of the ways UD researchers go the extra mile to engage K-12 students in science, technology, engineering and mathematics (STEM). 

McEllistrem is in charge of the expedition’s Ship2Shore educational program, which she developed with mentoring from fellow UD graduate student Cory Hite. Hite ran a similar program while researching rare earth elements in the Labrador Sea earlier this year. 

“I left for this cruise only a month after I moved to Delaware to start my master’s degree, so the amount of time to prepare for the research and the outreach was limited. The aid of the grad students at UD was essential in making this whole program happen,” said McEllistrem, who conducted similar video calls with K-12 students in classrooms across North Carolina and Indiana during the research cruise. “During my undergraduate studies at University of Minnesota Duluth, I found the geology and earth science departments to be so supportive and passionate, it became infectious and left me wanting to show people what a cool field of study this is.” 

Curiosity unlocked

Now, query a room full of adults at a conference if they have questions for the guest speaker, and you will likely hear a momentary pause of silence. But ask a room full of sixth graders who just toured a research ship, and these budding marine scientists were anything but quiet. They wanted details about everything — the ship, the rocks, the weather, the water, the wildlife. They wanted to know how many motors powered the research vessel and whether there was an anchor aboard (yes, but it’s only used closer to shore where it can reach the seafloor). 

One student wondered, “Does anybody go in the ocean to get the rocks?”

“Unfortunately, no. We have rules about getting in the water. Also, these rocks that the scientists are looking for are at a depth of 5,000 meters, roughly three miles below the surface of the ocean, and we can’t dive that far,” the captain replied.

“What is your purpose in collecting the rocks?” another student asked.

Warren explained that the research ship is situated above a fault line in the Earth’s crust that is on the seafloor, and that fault is moving at about the same rate as the San Andreas fault in California. 

“We are interested here in understanding earthquakes. Some parts of this fault have large magnitude earthquakes, while other parts do not,” said Warren. “And out here in the ocean, the rocks that make up the crust are much simpler and so we can understand better what is controlling the earthquakes. So, we need to get those pieces of rock.”

Most of the San Andreas fault has earthquakes, but one section of the fault is creeping along without any large earthquakes. The Chain fault has the opposite behavior — most of it is creeping and only a few parts have large earthquakes. With their work, the researchers are hoping to identify factors that cause creep instead of earthquakes. 

“What is the biggest rock you got from the seafloor?” came another question.

Warren explained that the biggest rock the team had dredged is a 3-foot-wide manganese rock weighing roughly 200 pounds. That is an estimate because the rock is heavier than the weight capacity of all the scales on the ship. The researchers aren’t sure what they are going to do with the rock because it is too large to cut on a saw. One possibility is to donate it to a museum so that it can be put on display, Warren said.

Other students wanted to know:

• How many days will you be at sea? 32 days total, with 22 days of science and 10 days spent in transit to and from the research location.

• How long is the ship? It’s about as long as a football field, approximately 272 feet long and 52 feet wide.

• Is there a way to get stuff you forgot once the ship sets sail? No. Once at sea, if you forget something or run out of something, like lettuce, you do without it. A lot of fruit and vegetables only last a few weeks. So, right now the crew and researchers are without lettuce and bananas, but they still have plenty of cabbage, carrots and apples.

• What animals have you seen from the ship? Starfish, bright red shrimp, squid, hammerhead sharks and flying fish, some of which even flew onto the ship.

“It was a great experience for the students, and they were so curious and engaged in learning about what [the researchers] are doing,” said Shoshana Kaplan, a math and science teacher that helped coordinate the experience for the entire sixth grade class at Wilmington Friends.

Meanwhile, the trip has been a transformative experience for McEllistrem. Her graduate thesis will focus on understandings gleaned from the rocks collected during the research cruise. The research team has collected a great set of "fault rocks" (called breccias) in the dredges. These rocks were cracked, fractured and ground up by earthquakes along the fault. According to Warren, there is a surprising variety in these rocks, so McEllistrem will be able to look for links between changes in the rocks and parts of the fault that creep versus parts of the fault having earthquakes.

“This program has been a welcomed learning opportunity for me, from learning operations on the ship, to teaching and community, this program has fueled my love for earth science even more. I hope the K-12 students we met with had an amazing time and some of them pursue futures in science,” said McEllistrem.

The National Science Foundation-funded project is a multi-institutional effort with researchers participating from Boston College, Boise State University, Indiana University Bloomington, Berea College and Woods Hole Oceanographic Institution. Additionally, two graduate students and a postdoctoral researcher aboard from Institut de Physique du Globe de Paris, France, contributed to the research from the lab of Cecile Prigent, who completed postdoctoral studies with Warren at UD and is now an assistant professor at the institute.