Uncooked pasta might be providing researchers with a better understanding of the effects of friction in earthquakes, according to a Penn State geoscientist.

Learning about the effects of friction forces in earthquake faults is important because friction plays such a large role in earthquakes, said Chris Marone, associate professor of geosciences.

"Everything about an earthquake relates to friction," he said. "It is essentially a frictional sliding event."

Marone used angel hair pasta as a last-minute replacement to simulate friction in a recent study.

Marone said researchers have done studies using numerical models, but that the computer simulations of earthquakes often produce unrealistic results.

"Computer simulations don't account for certain things, such as the roughness and dimensionality of the gouge [the debris between the two sides of the earthquake fault]," he said.

He said the numerical models use smooth particles that move in only one or two dimensions, but realistically the debris is made up of natural, angular particles with irregular surfaces that move in three dimensions.

"There are more complicated actions in the third dimension, such as rolling, sliding, dilation and compaction, and fracture," Marone said.

To incorporate these factors into the study, Marone, along with Kevin M. Frye and Karen Mair, two researchers from the Massachusetts Institute of Technology, experimented with both smooth and rough particles moving in all three dimensions.

"[We wanted to] test the effect of roughness in the third dimension," Marone said.

Using the "biaxial deformation apparatus" that they built in Penn State's Rock Mechanics Laboratory, the team tested the frictional effects of several materials. Quartz glass fiberoptic rods and angel hair pasta simulated motion in two dimensions, while smooth glass beads and quartz sand simulated motion in three dimensions, he said.

"Initially we planned on using the glass rods because they are simpler than [glass beads], since the rods only move in two dimensions," he said.

He said the angel hair pasta was not part of the original plan, but instead was used while setting up the experiment as a substitute for the glass rods, which had not arrived yet. The team was surprised to learn that the pasta worked just as well in the experiment as the glass rods.

"There turned out to be very little difference between the pasta and the glass rods, plus the pasta is cheaper and easier to get," Marone said.

He said the pasta used -- Ronzoni #12 Angel Hair -- cost $1.29 and came from a local grocery store, whereas the same amount of material in glass rods cost up to $800 and had to be shipped.

The results of the experiments thus far have proven that the roughness and dimensionality of the debris contribute more to the friction forces than numerical models typically show, he said.

"It turns out that particle roughness has a bigger effect on granular friction than we realized," he said. "We also observed differences between [movement in] the first, second and third dimensions."

Two of Marone's former students, Matt Knuth (junior-geology) and Chris Henty (junior-geosciences), are currently aiding Marone with his research.

"We set up and ran experiments before the break to make sure we could get repeatable results with the apparatus," Knuth said.

He said they have been involved with the research for about a month. They spend several hours a week preparing and running experiments and then analyzing the results with Marone.

"It's fun research to do, and the research that has already been done is interesting too," Knuth said.

Henty said he agreed that it has been a great opportunity.

"This is probably something I'd want to do as a career someday," he said. "One of my goals is to eventually help predict earthquakes, which is the ultimate goal of earthquake research."

Marone said he hopes that the results of their studies will be used to improve computer simulations, which could help to predict earthquakes in the future.

"Numerical models may try to incorporate the new findings," he said.

He also said they plan to experiment further with other types of pasta, such as spaghetti, vermicelli and capellini.