Earth’s Next Epoch

February 10, 2015

By Dr. E. Kirsten Peters

I was raised in the Baptist church. As a grade school child, I memorized the books of the Bible. Maybe because of that personal history, when I started to study geology I didn’t resist memorizing the many pieces of the geologic time scale. The next to the last piece of geologic time is the Pleistocene Epoch (known informally by many as the Ice Age). It is followed by the Holocene Epoch (the warm time we are living in now.)

The Holocene Epoch has seen the rise of human civilization. It is the time when people around the world started to shape the surface of the Earth through farming. From the kingdoms of ancient Egypt to the wars of the last century, the history you study in school occurred in the Holocene.

As a geology student I was taught that not only were we in the Holocene, but that we would be for the foreseeable future. But now there’s a move afoot to declare that we are in a new epoch. It’s not just a matter of names, but of our understanding of our place in the world. The new epoch is one in which we humans are taking over the reins from Mother Nature. The proposed new epoch is called the Anthropocene — from “anthro” for people.

Here’s the key: while we humans have been shaping the environment for thousands of years — through farming, early irrigation, and the cutting or burning of forests — our impact on the Earth has been rapidly accelerating.

It’s not easy to see exactly where we should draw the line that marks the start of our biggest impacts. Was it with the Industrial Revolution and the construction of modern cities?

A number of geologists think the line that marks the end of the Holocene should come a bit later.

What’s proposed now is that we declare the Anthropocene Epoch started near the end of World War II. That was the time humans exploded the first nuclear bomb and rival nations started testing nuclear weapons around the world, creating radioactive isotopes that fell to Earth in diverse environments.

This period also saw a new pulse in the increase in global population, as well as the start of industrialization in less developed nations. We poured artificial fertilizer onto fields and produced billions of tons of plastics. The Earth had never seen the like, as a group of scientists called the Anthropocene Working Group recently argued in the journal Quaternary International.

No matter where the line is drawn, the argument is clear that we are entering a new phase of Earth history, one in which we shape more of our own environment. Welcome to the Anthropocene — a time where we are in the driver’s seat. Let’s hope we steer the world as carefully as we can.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

To feed or not to feed?

February 3, 2015

By Dr. E. Kirsten Peters

During the winter I like to feed the birds. I have a very simple arrangement for this: pouring a mix of seeds on a flat railing outside my dining room window. I regularly attract several species of small birds to the seed.

Buster Brown, my mutt from the pound, has a role to play in the bird feeding. It’s his job to make the squirrels wary of coming up to the railing and stealing the seed. Buster has a dog-door, so he always has access to the area in question, and although he has never in his life caught a squirrel, he is glad to give chase. (Buster agrees with my mother that squirrels are really just rats with furry tails.)

Buster and I are really a team when it comes to squirrels. When I see one out the window on the railing, I call “Buster Brown, squirrel, squirrel!” My faithful dog then charges out the dog-door, putting him about 4 feet from the rodent. The chase is on, often going across the yard to where the squirrel can climb a tree where it scolds Buster to its heart’s content.

But am I really doing a favor to the birds by feeding them each winter? That question was the subject of a recent blog post by Joe Smith published by The Nature Conservancy. It turns out there’s a bit of scientific research on the matter.

Common sense suggests feeding birds during the tough, cold months helps them survive the most challenging of seasons. Our feathered friends need food energy to keep themselves warm, and winter limits the availability of food. Some scientific studies do agree with common sense: more birds survive the winter when they are fed than otherwise.

The Nature Conservancy blog post referenced a study in the upper Midwest of black-capped chickadees. Those fed by people had a higher survival rate over the winter (69 percent) versus those that weren’t fed (only 37 percent survived).

But for some birds in given locales, feeding may be, paradoxically, detrimental. Researchers in Great Britain discovered that certain fed birds laid fewer eggs the following spring and summer than did unfed birds. And the fledglings of the fed birds were less likely to survive than the offspring of unfed birds.

It’s not abundantly clear why fed birds would have less success with their offspring than unfed ones. It may be that store-bought bird seed isn’t really a balanced diet for birds compared to what Mother Nature provides, and there may be other factors, too.

Still, many studies suggest feeding the birds helps them out in tough times. That’s why, with the help of Buster to fend off the squirrels, I’ll continue to feed birds in my backyard.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

By Dr. E. Kirsten Peters

As you watch the falling snow, do you marvel at the beauty of the scene or immediately dread driving to work on icy pavement?

Most of our nation’s roads get at least some snow most years, and that means clearing snow and ice from pavement is big business. For highways alone, agencies in the U.S. spend $2.3 billion each season trying to remove snow and ice. And billions more are spent by local governments battling Mother Nature on city streets and county roads.

A traditional way of addressing roadway snow and ice is by spreading salt. In my home state of Washington, workers use about 4 tons of salt in each lane of a mile’s worth of pavement each year. In Minnesota the figure is 9 tons per lane per mile, and in New York it’s a whopping 12 tons.

“That reflects the fact salt is cheap in New York — and they have high traffic volume as well as lots of snow in places like around the Great Lakes,” said Professor Xianming Shi. Shi is a civil engineer at Washington State University. He researches new and better ways to melt ice on pavement or even prevent it from accumulating in the first place.

The problem with road salt is that it doesn’t vanish with the snow. Instead, via snowmelt, it trickles into groundwater and pollutes local streams and well water. The Environmental Protection Agency recently reported high levels of sodium and chloride, the ingredients of common table salt, in East Coast groundwater. The runoff from roadway salt threatens drinking water supplies, Shi told me.

For a number of years there have been some greener alternatives to spreading salt on roads. Any substance that lowers the freezing point of water can be helpful. One alternative substance that’s well established is a waste product from sugar beet refining.

“That’s a well-known, patented technology,” Shi said.

Shi and his research team are looking at local wastes that can be upcycled for winter roadway operations. These materials range from residue from wine production to materials from flower growers and the biodiesel industry.

Another goal of the work is to find substances that are less corrosive but achieve the same level of pavement friction.

“Magnesium chloride is sometimes sprayed on roads to combat ice,” Shi said. “But magnesium exchanges with calcium in concrete at depth.”

That exchange weakens the concrete, a bit like an elderly person losing bone mass. Overall, the strength of the concrete can be reduced by up to 50 percent.

“So we need to design concrete to better withstand exposure to magnesium chloride,” Shi told me.

It would be wonderful, of course, if pavement resisted the accumulation of ice. The texture of pavement can be manipulated to some extent to resist ice buildup. Nano- and micro-sized particles can be added to concrete to weaken its bond to ice or compacted snow.

“It’s more costly,” Shi said. “Still, it can be useful in some places, like in mountain passes.”

There’s some good research in progress at WSU. But while waiting for further developments, don’t throw out your back as you shovel.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

By Dr. E. Kirsten Peters

Recently I had the pleasure of going to the wedding celebration of my assistant at work — whom I count as a good friend — and her new husband. Theirs is an international marriage: the bride was born and raised in this country, the groom born and raised in China. The wedding celebration had elements of traditions from both the U.S. and China: the bride wore red, as is the custom in China, and the marriage was celebrated with a ring, as is the custom here.

Engagement and wedding rings interest geologists from a technical point of view. Long ago, I did geologic research related to gold mining. My Ph.D. thesis was on gold-bearing hot springs in California and the associated gold-mercury ore in the ground. Gold has been a precious metal since time immemorial. Its warm color and the fact it doesn’t tarnish made it a favorite for jewelry long ago. So even though the hot springs stank of sulfur, they smelled like gold to me.

The wedding I went to featured a traditional gold ring with a diamond solitaire. Apparently, it bucks the trend of what’s in fashion these days — when many engagement and wedding rings are made of “white gold.” What, you may ask, is “white gold” when gold — the metal itself — is known for its warm yellow color?

The answer depends, in part, on understanding that gold in jewelry is an alloy, a mixture of gold and other metals that have various properties. In the jewelry biz, the purest gold is called 24 karat. It’s 99.7 percent gold. Eighteen karat gold is 75 percent gold. Fourteen karat gold is about 58 percent gold.

Why not use pure gold in jewelry since the color and value of the metal are so high? Twenty-four karat gold is too soft to be used in jewelry that gets worn every day. Other metals added to the gold make it more durable. When metals are mixed, they create alloys. A wide variety of alloys are available in jewelry. Here are the ingredients of just two types of gold alloys you may see in stores:

“Red gold” can be a mixture of gold and copper.
“Green gold” can be an alloy of gold and copper, possibly with some silver, and a little bit of cadmium.

It makes sense that higher karat gold tends to be more golden in color — it’s the addition of other metals that makes a variety of other colors possible.

To get back to the white gold that’s in fashion for wedding rings these days: it can be a mixture of gold and palladium, nickel, manganese, copper, silver or zinc.

The color of white gold doesn’t come from the alloys in the ring itself. Rather, white gold jewelry has a coating of a metal called rhodium. It’s the rhodium that makes white gold rings white in color.

Personally, I’m glad my friends went with a traditional golden band. It is, to my old mind, “as good as gold” — as I hope their international relationship will be for the decades to come.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

By Dr. E. Kirsten Peters

Like most regions of the country, the area where I live suffered through colder than average temperatures in mid-November. If you pay for your heating bill month by month, you are now facing the sticker shock that results from those bitter times. Happy holidays.

I heat my home with a natural gas furnace supplemented by a woodstove in the living room. It’s a small stove, really designed only for emergencies and for fires built for fun on a Sunday afternoon. In other words, it doesn’t heat the whole house, and it works only with constant tending. But during our cold snap, I built some fires in the woodstove to try to take the edge off the natural gas bill I was incurring. The woodstove is in the same room as the thermostat for the house, though, so heating with it caused the temperatures in the rest of the house to crash. Still, I was doing what I could to lessen what I would later owe the power company.

The main ingredient in natural gas is methane. It’s colorless and odorless, so utility companies add a “rotten egg” smell to it. That way, if there is a leak, your nose becomes aware of it and you can evacuate your home, then call 911.

Methane occurs elsewhere in the solar system besides the Earth. It’s abundant on Titan, one of the moons of Saturn. On Titan, methane is a liquid because temperature there is almost 300 degrees below zero Fahrenheit. Scientists have now plumbed the depths of three frigid seas of methane on Titan. An article online at told me that the second largest of the seas, called Ligeia Mare, holds enough methane to fill Lake Michigan three times.

NASA’s Cassini probe reached the neighborhood of Saturn in 2004 and it’s still sending back data. The spacecraft was told to send radar pulses directed toward Titan’s seas. Results in some places included two sets of reflected energy. The first set of waves were from radar bouncing off the surface of the methane sea. The second, weaker, set of waves were from radar bouncing off the floor of the methane sea, under the surface. Together, these indicate the depth of the liquid methane.

The shallow parts of the sea are some 20 to 40 yards deep. In other parts of the Ligeia Mare, however, the methane is so deep no reflections from the bottom were detected, indicating places that are more than 200 yards deep.

It’s amazing to me what we are continuing to learn about our solar system — information ranging from data beamed back from a spacecraft landing on a comet to this information about Titan’s methane seas. I’m also amazed by what I owe the power company for methane I used in November — but I’m trying to keep some perspective about it.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

Keeping warm with gold fever

December 22, 2014

By Dr. E. Kirsten Peters

I own a couple of small gold nuggets. They came from the Round Mountain gold mine in Nevada, which I visited a few years ago. A tour of the open-pit mine was crowned by a visit to their foundry where the molten metal was poured into gold bars. Those bars are what’s called doré gold, that is, it’s the metal as it comes out of the ground with minor impurities in it like silver. The doré bars are then transported to a refinery where pure gold can be separated from other metals. I got to heft one of the doré bars, and I can attest that gold is, indeed, remarkably dense.

A mega-gold nugget found in California was in the news recently. It was large enough to about fill a human hand and weighed just over 6 pounds. That’s about 75 troy ounces. It was dubbed the “Butte Nugget” because it was found last summer in Butte County, supposedly on public land. The nugget sold for about $400,000 to a buyer who chose to remain anonymous.

News reports — sketchy because of the secrecy of the discovery and sale — said the nugget was found with a metal detector. When the detector indicated an extremely strong signal, the operator thought he had likely found a piece of pipe or a horseshoe. Happily, he had the good sense to dig down about a foot into the soil where the nugget lay.

Gold occurs in the Earth in two main forms: as lode gold or as placer gold. Lode gold is found in veins, usually made of quartz, that cut across rocks. You may recognize the word “lode” as part of the famous idea of the Mother Lode, the mythical deep and rich vein thought to be that from which other smaller veins branch off. If you find the Mother Lode, your financial problems are over.

When gold veins occur at the surface of the Earth they are broken down, or weathered, by water. The quartz in the veins crumbles into quartz pebbles and sand. The gold is liberated from the vein material, falling out as loose nuggets or small gold grains that can be as fine as sand. Because gold is dense and doesn’t react with water under most conditions, loose gold can accumulate and form what’s known as placer gold ore. In streams, placer gold is found where running water slows down and the gold settles out: on the inside bend of turns in streams and behind boulders.

Patience, a good metal detector, and lots of luck can clearly still lead to stupendous gold nugget finds. Like winning the lottery, dreaming of mega-nuggets keeps hope alive even in the dark days of December. Writing about this subject makes me think that, as I sit by the fire in my woodstove one evening this week, I’ll get out my little gold nuggets to remind myself of longer days and outdoor activities we can look forward to in the New Year.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

By Dr. E. Kirsten Peters

What if there were a two-for-one sale on kilowatts? Your power bill would be cut in half — not a bad result for your monthly budget.

Energy drives everything we produce and consume, and global energy consumption continues to grow year after year. The two-for-one image came to mind as I talked with Professor Jeanne McHale of Washington State University. McHale is a chemist who researches an alternative approach to making solar cells that produce electricity.

“There’s no question we have a lot of solar energy that strikes the planet each day,” McHale told me. “It’s an often-quoted statistic that just one hour of sunlight all over the planet has enough energy to give us what we need for a year.”

The challenge is capturing that energy at economical rates. Traditional solar cells are made of expensive and high-tech ingredients. They work, but at a relatively high price and with negative environmental impacts. For some time now, scientists have been looking at an alternative version, called dye-sensitized solar cells. Most researchers use synthetic organic dyes or dyes containing an element called ruthenium. The McHale lab is one of the few using plant dyes.

McHale studies pigments like betanin, one of the molecules that makes beets red. Betanin can be used in these alternative solar cells. Recently McHale and her team found a way to have each photon striking the betanin produce two electrons.

“This means we could double the electrical current of dye-sensitized solar cells,” McHale told me.

One of the challenges for McHale is that a one-electron reaction occurs in parallel with the desired two-electron reaction, producing what chemists call a “free radical.” Those are highly reactive and damaging molecules. The free radicals in the dye-sensitized solar cells damage the betanin. Currently McHale is working on what are called co-pigments — molecules that can be attached to betanin to make it more stable under the influence of free radicals.

“The way I think of it is that we have a molecule that’s a model: one that can help us design better molecules that would produce two electrons per photon without the degradation problem,” McHale said.

Calculations show that the maximum possible efficiency of dye-sensitized cells is about 30 percent. What’s been achieved so far is 13 percent. That doesn’t sound too good until you learn that plants — in their process of photosynthesis — have an efficiency of about 1 percent.

“The joke is that if plants went to the government for funding, they would never be awarded a grant,” McHale said.

Although I’m a geologist who spent part of her early career studying the geology of fossil fuels, I think that securing more of our energy needs through solar power would be potentially good for the planet and a triumph of sophisticated science. Here’s wishing McHale’s lab the very best!

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

Wake up and smell the genes

December 15, 2014

By Dr. E. Kirsten Peters

Like millions of Americans, my day starts by plugging in the coffeepot. In my case, it’s an old fashion percolator. It clears its throat and brews my coffee while I rub sleep out of my eyes and brush my teeth.

My habit of starting my day with coffee — and following that initial cup with doses of java in the mid-morning, the late morning and the early-afternoon — may be at least partially grounded in my genes.

Researchers have long believed that genetics influences a person’s daily coffee consumption. Early this fall, a new study fleshed out just how many variations in genes may be involved in determining who drinks a lot of java.

Marilyn Cornelis of the Harvard School of Public Health helped orchestrate the research published in a journal called Molecular Psychiatry. The work rested on about two dozen previous research projects that had a total of about 120,000 subjects. That’s a big group, made up of people who answered questions about how much coffee they consumed and then donated a sample of their DNA to researchers at the Harvard School of Public Health and Brigham and Women’s Hospital in Boston.

In the past, scientists had identified two genetic variants that “code” for coffee consumption. Now six new gene variations have been found to be common in people who drink a lot of coffee and other caffeinated beverages. Four of the newly discovered variants are linked either to the stimulating impact of caffeine on the body or to how we break down caffeine — two loci (POR and ABCG2) change the metabolism of caffeine; two other loci (BDNF and SLC6A4) appear to relate to how rewarding is the experience of caffeine.

The last two loci (GCKR and MLXIPL) found in the study were not expected: they are not clearly associated with caffeine but rather act to control blood sugar and cholesterol levels. It’s not known how they relate to the propensity to quaff coffee and other caffeinated beverages.

Cornelis told the New York Daily News that the genetic variants don’t correspond to how strong coffee tastes to an individual. That result surprised her, as it does me.

The Harvard Gazette also wrote a piece on the findings. It mentioned the fact that some studies have shown benefits from drinking coffee each day. Cornelis has not been a coffee drinker, but because of some of the information coming out in recent years, she is giving java a go.

I wish Cornelis well in her personal experiment. I can admit I didn’t like the strength and taste of coffee when I first tried it in college. But now I think coffee tastes good and, to me, the taste of good coffee seems quite mild. I also think coffee-flavored ice cream is grand – in particular when it comes with a cup of hot coffee on the side.

Maybe my love of coffee was determined when my genes first formed in utero. It’s an interesting thought.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

How much does it hurt?

December 1, 2014

By Dr. E. Kirsten Peters

When I take my elderly mother to the emergency room, the nurse asks how much pain she is in, on a scale of 1 to 10. There is a chart with pictures of little smiley faces, neutral faces, and grimacing faces to help a person — perhaps a child — determine a number. Pain management is an important part of human medicine.

Despite what the 17th century philosopher and naturalist René Descartes said about animals being merely organic machines, it’s clear to me they feel pain in a manner similar to us. But we can’t ask Fido or Felix to tell us what they are experiencing. That point has been abundantly clear to me recently because my 11-year old mutt from the dog pound, Buster Brown, is having arthritic pain in several weight-bearing joints. He gets up from a lying position with difficulty, and he takes the stairs slowly and only when he must.

“In veterinary medicine, we have pain scales similar to what they use in the ER, but they are based on our observations,” Dr. Raelynn Farnsworth told me. Farnsworth instructs vet students at Washington State University’s veterinary teaching hospital.

Farnworth showed me a four-point scale with sketches of dogs in various positions and written descriptions of the way the dogs are behaving. Vet students are trained to assess animals and locate them on this type of pain scale.

“We go on what we can observe, our examination, and what the owners tell us about how the animal is behaving at home,” Farnsworth said.

Practicing veterinary medicine rather than the human variety has other challenges than assessing pain. Medications that are helpful to dogs are not all good for cats. Drugs good for people can kill an animal.

“You’ve got to check with your vet before you treat your animal for pain,” she said. “One thing your vet may discuss with you is pre-treating your animal, say before a big walk, if you know he’s likely to be sore afterward.”

The good news is that veterinarians now treat pain more aggressively in animals and there are also a wider variety of medications that are available to help.

“Many of the pain meds we use now were new or not available at all when I started practicing 21 years ago,” Farnsworth said.

Years ago, it was sometimes considered good to keep an animal in a moderate amount of pain after surgery, so the animal wouldn’t move around a lot and tear out stitches. But those days are long gone. Veterinarians treat pain aggressively now. That strikes me as more merciful.

Fortunately, the news from my household is good. Buster Brown has been taking an anti-inflammatory and two supplements in recent weeks and he is getting around much better. He goes by me at a canter when we are outside, he runs up and down the stairs, and he stands up from a lying position without the difficulty he was displaying earlier this fall. I’m greatly relieved — I like to think that pain isn’t bothering him nearly so much, and I hope I can keep him in the land of the living a good while longer.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.

How ‘bout them apples?

November 24, 2014

By Dr. E. Kirsten Peters

Do you have a good gut feeling about apples? Your body may — and that could be important to your overall health.

Some of the components of apples survive their trip through the upper part of the human digestive tract. Non-digestible compounds, including fiber and substances called polyphenols, stand up to chewing and the effects of enzymes in spit. They even remain intact after a bath in stomach acid. These compounds move all the way to the colon, where they undergo a transformation that can be quite beneficial to you.

The non-digestible compounds are fermented in the colon. That’s right, you could say you have a little brewery at work in your body. The fermentation allows for the growth of certain bacteria in the gut.

Which bacteria flourish in your colon really matters. Studies have shown that obese mice have different bacterial families and diversity of bacteria in their gut than do lean mice.

Now researchers at Washington State University have concluded that apples — especially Granny Smith apples — may lead to healthy bacteria in the colon and this, in turn, may help prevent a variety of medical disorders.

“Apples are a good source of non-digestible compounds,” Professor Giuliana Noratto told me. “We have now studied the differences in apple varieties to look for the most useful types.”

Results of the study were recently published in the journal Food Chemistry by Noratto and her co-researchers Luis Condezo-Hoyos and Indira P. Mohanty.

The new research indicates that Granny Smiths contain more non-digestible compounds than many other apples including Braeburn, Fuji, Gala, Golden Delicious, McIntosh and Red Delicious.

As a first step toward understanding the gut processes better, Noratto’s team simulated colon fermentation in test tubes. Fecal bacteria were cultured in apple compounds that survived gastrointestinal enzyme digestion.

“The non-digestible substances in the Granny Smith apples actually changed the proportion of fecal bacteria from obese mice to be similar to what you find with lean mice,” Noratto told me.

Now Noratto is feeding Granny Smiths directly to rats. This takes the ideas suggested by the test tube experiments and tries them out in the real-world condition of flesh-and-blood guts. Noratto expects results from the animal trials sometime in the New Year.

One thing about the rats interested me as an aside. The obese and lean rats are fed the same number of calories each day. But a high fat diet produces overweight rats, while a lower fat diet leads to lean rats. I’ll try to remember that the next time a bowl of ice cream is calling to me.

Down the road, Noratto’s work with apples could be important in the battle of the bulge that so many of us face. Beyond that, it could be useful in combatting diabetes. From Noratto’s perspective, obese people have an unfortunate community of bacteria in their gut. The bad bacteria make for byproducts that can lead to inflammation and influence metabolic disorders associated with being overweight.

It would be interesting if modern science can show that “an apple a day” really is a helpful addition to the human diet. Stay tuned!

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.