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Tracking the buildup to volcanic eruptions

June 15, 2017

ASU scientists develop technique using tiny crystal 'time capsules' to trace pulses of heat inside a volcano; may help better predict risk

Volcanos that erupt explosively are the most dangerous in the world. When they blow, they eject giant clouds of hot ash mixed with gases at temperatures up to 2,000 degrees Fahrenheit that engulf everything in their way. 

A new technique developed by Arizona State University scientists, working with colleagues in California, Oregon, Michigan, Singapore and New Zealand, lets scientists track the heating history of the molten rock, or magma, that feeds explosive volcanos. The technique uses tiny crystals of zircon that form within the magma. 

The picture coming from the new research, published June 16 in the journal Science, suggests that pulses of heat in the magma before a volcanic eruption both begin and end more abruptly than scientists previously thought. Moreover, the heat pulses last a shorter time than expected. 

The new findings will change how scientists view the internal workings of all volcanos, and it may help them gain a better idea when an active volcano poses the most risk.

The team gathered debris that erupted from New Zealand's Mount Tarawera about 700 years ago. That eruption, roughly five times the size of the 1980 Mount St. Helens eruption, brought to the surface magma that recorded the volcano's thermal history, including the heat pulses leading up to the eruption.

Tiny bits tell a tale

The magma contained zircon crystals, each less than a millimeter long, which were the focus for the ASU scientists on the team. 

"For the first time, we can tell how long ago a given zircon crystal formed — and we can also measure how many heat pulses it has experienced," said geochemist Christy Till, assistant professor in ASU's School of Earth and Space Exploration. She is a co-author of the Science paper. 

"In addition," Till explained, "we can tell how hot those pulses were and how fast the crystals cooled after each of them." This lets geo-scientists build a detailed heat timetable of a volcano's past activity, including what occurred long before any historical records.

"We were especially interested in what events lead up to an eruption," Till said. "To our surprise, we discovered that these zircon crystals are telling us that they mostly led a very sedate, boring life."

The zircon crystals from Mount Tarawera had formed at least tens of thousands of years ago inside the volcano, as molten rock cooled, Till said. "Over their lifespan, they experienced only a few brief heating events, whereas we had expected to see more prolonged pulses of heating."

The secret to the new findings is an advanced mass spectrometer at ASU, one of a small handful of similar instruments in the United States. 

"The key to tracing the thermal history of these crystals is our NanoSIMS instrument," said ASU Research Assistant Professor Maitrayee Bose, who will join the School of Earth and Space Exploration faculty in August. The "SIMS" in the name stands for Secondary Ion Mass Spectrometry, and the "nano" part underscores that it works on very small scales.

As Bose said, "In essence, the NanoSIMS is a highly complex microscope that gives precise information about the elemental and isotopic composition of samples no wider than the width of a human hair." This extreme resolution let the scientists trace successive heat pulses that left marks in the crystals like tree rings.

How does push become bang?

Although the discovery involves microscopic-sized crystals, the results will likely have a large effect on the field of volcanology.

"Our idea of how the magma reservoir below a volcano behaves has evolved a lot over the last 10 or 15 years," Till said.

"It's no longer seen as a big blob of magma that resides below a volcano," Till explained. "Instead, these magma bodies are the result of many smaller injections of very hot magma into a cooler mush of crystals and older magma that lies in the shallower parts of the volcano's interior."

Yet how these injections combine to make an eruption is a matter still to be understood, Till said. As scientists track how heat pulses cool off and magma turns mostly into solid crystals, a basic question keeps returning: What causes a volcano to erupt? 

"It's a process we don't really understand yet," Till said. "Maybe a very large pulse of magma triggers the volcano to blow, or it could be more complicated. Maybe there's another process in which the magma cools off, forms crystals — and out of the still-hot residue, bubbles of gas form which causes the eruption.

"We simply don't know yet."

Top photo: New Zealand's Mount Tarawera volcano has erupted many times. Here an outburst in 1886 broke open a dome of rhyolite rock built by an eruption about 700 years ago. This open rift let the scientists collect tiny zircon crystals from the earlier eruption's debris, visible as outcrops of white-toned rock. Photo by Kari Cooper

Robert Burnham

Science writer , School of Earth and Space Exploration


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ASU celebrates ancient practice of yoga

Open ASU event Saturday in honor of International Day of Yoga, which is June 21.
Yoga comes from an ancient Sanskrit word meaning "to unite."
ASU expert: 5-10 minutes of yoga a day better than single 1.5-hour class a week.
June 15, 2017

Learn more about the practice, history and benefits from ASU's experts; take part in community event this weekend

Thirty years ago the phrase “downward dog” was likely to raise a few eyebrows when overheard in conversation, but nowadays you’d be hard-pressed to find someone who doesn’t recognize it as a yoga pose.

The United Nations seemed to think so when in 2014 it sought to give the more-than-5,000-year-old practice the recognition it deserved by establishing June 21 as the International Day of Yoga. From 6:30 to 8 p.m. on Saturday, June 17, the Arizona State University student chapter of the Art of Living Foundation will host a community yoga celebration on the Tempe campus’ Hayden Lawn.

The gathering is part of a nationwide event to spread awareness of the practice, and an estimated 50 to 100 people are expected to show up, according to Alicia Nelson, global studies undergraduate and president of the Art of Living ASU student chapter.

Nelson took her first yoga class at ASU a few years ago and began teaching it around the Valley in early 2016.

“Yoga is that time where you say, OK, I’m going to pause everything I’m doing in the outside world and focus on what’s going on inside,” she said. “When you give yourself that time, you’re more aware of how you’re going through life, and it gives you the power to have a deeper experience and come to happiness in the moment.”

Yoga featured prominently at the recent opening of ASU’s Center for Mindfulness, Compassion and Resilience, a new initiative that will bring together researchers, practitioners and educators across disciplines to collaborate, study and spread ideas about mindfulness, compassion and resilience throughout the university and surrounding community.

“I’m really excited about the new center,” ASU health sciences lecturer Julia PearlJulia Pearl is a lecturer in ASU’s School of Nutrition and Health Promotion. She holds the following certifications: E-RYT 500 (Experienced Registered Yoga Teacher); YACEP (Yoga Alliance Certified Education Provider); ACSM-CPT (American College of Sports Medicine, Certified Personal Trainer); and AFAA- CGFI (Aerobics and Fitness Association of America, Certified Group Fitness Instructor). said. She has been teaching yoga since 1995 and hopes to incorporate her specialty, Ashtanga yogaAshtanga yoga is a style of yoga popularized by K. Pattabhi Jois during the 20th century and consisting of eight “limbs,” or branches, of which physical poses are only one. “Power yoga” is a generic term that may refer to any type of aerobically vigorous yoga exercise derived from Ashtanga yoga., into the center’s offerings.

In preparation for Saturday’s event, ASU Now tracked down some of the university’s foremost experts on yoga to create a mini guide on its practice, history and benefits.

Video by Deanna Dent/ASU Now

An age-old practice

The word “yoga” comes from an ancient Sanskrit word that means “to unite,” as in uniting the body, mind and spirit. The practice originated in India more than 5,000 years ago with the goal of enlightenment and self-realization.

“In almost any culture, there’s this desire to understand why are we here, and now that we’re here, how do we live this life,” said attorney and Desert Song Healing Arts Center yoga instructor Alisa Gray. “People have always sought answers to these questions, and we’re still seeking answers.”

Desert Song Healing Arts Center is a community partner of ASU’s Center for Mindfulness, Compassion and Resilience. Gray, who earned her undergraduate and law degree from ASU, also teaches yoga and mindfulness to law students and legal professionals.

Gandhi, as it turns out, was also both a lawyer and a yogi, though not in the sense we might think. He practiced Ahimsa, or non-violence.

“Gandhi was a yogi in the sense of practicing what’s called karma yoga — good works,” Gray said. “So he was a yogi although you wouldn’t see him doing downward dog.”

Western vs. Eastern

Yoga only recently became commonplace in Western countries. Some trace the origin of yoga in the West to the yogi Swami Vivekananda’s visit to the Chicago World’s Fair in 1893, where he demonstrated various poses. Almost a century later, during the 1970s, University of Massachusetts Medical School professor Jon Kabat-Zinn helped boost its popularity in the U.S. when he integrated the teachings with scientific findings.

Since then, yoga has seen the endorsement of celebrities like Sting and Madonna and has even been incorporated into professional athletes’ training regimens.

“Gosh, it’s changed so much over the last 22 years,” Pearl said. “The biggest way is just how mainstream it’s become. … It’s very normalized. Much more so than when I first started in Seattle, when I was involved in the ‘Earthy-mama’ movement.”

And yoga is no longer thought of as a solely religious practice meant to achieve enlightenment.

“Western yoga is definitely more fitness-oriented,” said ASU health sciences lecturer Christina BarthChristina Barth is a lecturer in ASU’s School of Nutrition and Health Promotion. She holds the following certifications: Registered Dietitian Nutritionist; Registered Yoga Teacher., “but it still helps us to manage stress, learn to relax and increase our overall sense of well-being.”

More than just striking a pose

There are several schools of yoga, including Bikram (hot yoga), Yin (slow-paced) and Ashtanga (power). One of the main components of Ashtanga is deep breathing, which Pearl said “almost sounds like Darth Vader” in an otherwise quiet studio.

That breathing aspect is very important, though. In fact, breathing is one of the eight “limbs,” or branches, of yoga. Other limbs include meditation and ethics.

The poses we generally associate with the entirety of yoga actually only make up one limb, called the “asana” limb, and there is some debate among yogis as to where they all came from, since ancient writings mention just one: the seated meditation pose. One theory, according to Gray, is that the plethora of modern-day yoga poses originated from calisthenicsCalisthenics are gymnastic exercises intended to achieve bodily fitness and grace of movement..

There’s also the mental and emotional aspects of yoga to consider, said Devi Davis-StrongDevi Davis-Strong is a lecturer in ASU’s School of Nutrition and Health Promotion. She holds the following certifications: Yoga Alliance 200 Hour Teacher Certification; American College of Sports Medicine Health Fitness Specialist and Personal Training Certificate; American Council on Exercise Group Fitness and Personal Training certifications; Certified Health Education Specialist., ASU exercise science and health promotion lecturer. It’s those aspects, as opposed to the physical poses, that have kept her coming back over the roughly 15 years she has been practicing.

“The poses are challenging, but that’s not really the point of yoga,” Davis-Strong said.

Research to back it up

Among the benefits of yoga are lessened insomnia, anxiety and depression; lower heart, respiratory and blood pressure rates; increased serotonin levels; and improvement in body image. And those benefits have been scientifically proven, something that satisfies Westerners’ desire for empirical justification, Gray said.

Barth, who has been doing yoga for 10 years, has seen firsthand the positive effect it has had on clients at her private practice, who are recovering from eating disorders.

“I’ve seen a big change in them as far as mindful eating,” she said.

Research has also shown that yoga can shift the body from a state of “fight or flight,” our bodies’ natural response to stress, to a more relaxed one.

“We live in such a fast-paced, stressful society, we need a way to calm ourselves, to soothe ourselves,” Davis-Strong said. “The stress response is quick; it’s a survival mechanism” that can muddle the circuitry in our frontal cortex, which helps us make good decisions. “Yoga can help us slow down so we can make better decisions and respond better to challenging situations.”

Anyone can be a yogi

Incorporating yoga into your life could be easier than you thought. Pearl recently helped create a video demonstrating 10 stress-relieving postures that can be done at your desk.

“You don’t even have to go to a gym; you can practice mind-body exercises at your desk when you get an email that makes your blood pressure go up,” she said. “You can do something about it right then that will be better for your well-being.”

When it comes to setting goals, she advises against putting too much pressure on yourself or forcing yourself to do something that’s too difficult.

“With all behavior change, it’s really about starting with the ‘smart’ goals: specific, measurable, attainable, realistic and time-oriented. Things that somebody will actually be able to do, because consistency is key. If you can do five to 10 minutes of yoga a day, that’s better than one, one-and-a-half-hour class a week,” Pearl said.

Adding to that, Davis-Strong said it’s important not to be intimidated and to just enjoy the experience.

“I just encourage people to give it a try and see how they feel,” she said. “Just feel good, have fun and enjoy your body.”

Sun Never Sets on Yoga

What: Yoga session open to the public.

When: 6:30-8 p.m. Saturday, June 17.

Where: Hayden lawn, Tempe campus.

Admission: Free; donations accepted.

Details: Bring mat, water bottle and small meditation cushion. Find more information at ASU Events.

Top photo: ASU health sciences lecturer Julia Pearl does yoga at ASU's Sun Devil Fitness Complex on the Downtown Phoenix campus. Photo by Anna Werner