Europa has a thick crust of ice over an ocean. Lake Vostok, miles beneath the Antarctic ice, is similar. But lessons from one may not apply to the other. NASA image

It was a thrill to learn that on Sunday, Russian scientists managed to poke a drill tip through miles of Antarctic ice into Lake Vostok. Samples of water from this extreme environment promise to provide one of biology's severest tests of life on Earth. Scientists are talking up the possibility that this experiment, the first of several in progress in Antarctica, could tell us more about possible life on the icy satellite of Jupiter named Europa. Is that a stretch?

We're asking different questions here. At Vostok, we want to know if life has survived; at Europa we want to know if life could have arisen. In that context I think that Vostok and Europa are worlds apart; their similarities are superficial. Let's look at the two places in a bit more detail.

Lake Vostok is a large tectonic basin, rather like Lake Tahoe, that happened to be overrun some 15 million years ago by the growing Antarctic ice cap. It has been sealed in profound darkness and freezing cold ever since, with the ice flowing slowly over it. Here's a diagram of the situation.

National Science Foundation image

The lake is kept unfrozen because of a trickle of heat from the Earth's crust beneath plus the effect of great pressure in depressing the freezing point. Ice melts at the upstream end and lake water freezes at the downstream end, so on the geological time scale there's an exchange of water, and the water itself must be charged with air carried in by the ice. But the amount of minerals and nutrients entering the lake this way must be astronomically small. Somewhat larger amounts may come from the rock and sediment of the lake's floor, but the picture is still disheartening.

And yet we have found life everywhere on Earth, from temperatures above the boiling point to below freezing. Microbes are recovered from within the ice cap itself. I believe that the microbes originally sealed into Lake Vostok survive today, because that's the way to bet on this planet. However, from everything we know, life could never have arisen in such a place. The raw ingredients and energy required are absent.

Is that true for Europa? It's colder on its warmest day than anywhere on Earth, true. But Europa should have much more of the assets for life than Vostok.

Europa is an old world that formed along with the rest of the planets. Like Earth, Europa separated into a dense interior and a light shell, only with a greater share of water. Its rocks, like those of the early Earth, had lots of natural radioactivity that must have generated enough heat to keep part of the overlying water melted throughout its history. (More recently, Jupiter's four major satellites have fallen into mutually resonant orbits that wring them with changing tidal forces. The innermost moon, Io, is heated to volcanism this way, and Europa and Ganymede are heated to lesser extents.) The heat must have expressed itself in hydrothermal vents, too, exactly like Earth's seafloor "black smoker" vents.

In a word, as far as planetary scientists can tell Europa should have started out with the same setting that is commonly thought to have spawned life on Earth. The first structures that served as cell membranes could have arisen at hydrothermal vents, which would exist on Europa just as they do on Earth: springs of hot, chemically active water on the floor of a big cold sea. The water itself should contain ammonia, sulfates, even hydrocarbons. All of this is straightforward modeling based on what we already know about the solar system.

Model of the icy crust of Europa. Jet Propulsion Laboratory image

Planetary modelers are finding that the thick ice shell of Europa should have some interesting activity, too. The eerie striped pattern of Europa's surface shows that the ice fractures regularly due to tidal forces. When that happens, water would rise and its dissolved gases would come out in bubbles. These "Perrier ocean" eruptions would spray over the surface, where the ice and its organic compounds would bake and polymerize and react in the radiation from Jupiter and the Sun.

Eventually, after approximately a billion years, the entire icy crust would become replaced with ice bearing this baked material. And at that point you would have a nutrient cycle. In sum, it's quite plausible for life to arise and persist on Europa where it's quite impossible in Lake Vostok. If we ever get a spacecraft to Europa—proposals keep being submitted—our experience drilling to Vostok would help us drill through Europa's crust. But a more elegant proposal is to simply swoop over Europa in low orbit and scoop up bits of dust from its icy surface raised by micrometeorite impacts. Just like on Earth, if life is on Europa its signs should be everywhere.

Will gray wolves return to California? Photo: MacNeil Lyons, National Park Service/ U.S. Fish and Wildlife Service – Midwest Region.

When a gray wolf wearing a GPS collar crossed from Oregon into California in December, it was the first wild gray wolf to tread on California soil since the 1920s. Wolves once roamed throughout California, and some people think packs may prowl the state again. It is debatable whether this lone wolf is a sign of things to come, but if wolves return to California, their role in the ecosystem will be different than it was in times past.

Until the early 1900s, gray wolves (Canis lupus) lived throughout much of North America. They were present in California’s Sierra Nevada Mountains, the Coast Range, and the Central Valley, among other locations. Their range was not well documented. Gray wolves are predators; they hunt in packs and eat all kinds of prey, from small rodents on up to Bison. Their main prey items were Tule Elk and Pronghorn, an animal similar to an antelope.

As California’s Central Valley was converted to agricultural fields and pastures, the number of Tule Elk and Pronghorn dwindled. A shrinking supply of wild ungulates (hoofed mammals, such as elk, Pronghorn, and deer) meant that wolves started going after livestock—with major repercussions. Predator control programs led to extinction of the gray wolf in the lower 48 states. In 1924, the last known wolf in California was trapped and killed in Lassen County.

Gray wolves were added to the Endangered Species List in 1974, shortly after the Endangered Species Act was passed. Then, in the mid 1990s, gray wolves from Canada were re-introduced to Idaho and to Yellowstone National Park.

The gray wolves introduced to Idaho expanded their range, and there are now about 1600 wolves in the Northern Rocky Mountains and Pacific Northwest. In Idaho, there are concerns that the local population is growing too large, and the wolves are getting too close to human habitation. Last year, gray wolves were de-listed in certain areas, where it became legal to hunt them. Five wolves were killed via aerial gunning in Idaho.

Studies on the wolves in Yellowstone, conducted by Chris Wilmers, Assistant Professor in the Environmental Studies Department at the University of California Santa Cruz, have found that gray wolves buffer the effects of climate change for other carnivores. Many scavengers, such as bald eagles, coyotes, and black bears, feed on elk carcasses during the winter. After heavy snowfall, elk become exhausted from walking through deep snow and eventually expire. However, winters are becoming shorter as a result of climate change, and there are fewer elk carcasses to be scavenged. After wolves were released in Yellowstone, their hunting activity increased the availability of food for scavengers.

The Gray Wolf that recently crossed into California—named OR7 and re-named “Journey” in a naming contest—split off from his pack in Oregon. Wolves can outgrow their packs and will disperse to find a mate. As the only known wild gray wolf in the state, is highly unlikely that Journey will find a mate. And without a pack to hunt with, this lone wolf will probably need to scavenge for food. Journey probably won’t father California’s future wolf population, but it is possible that other Oregon wolves may follow in his nearly 1000 miles of footsteps.

California has suitable habitat for gray wolves, and has plenty of potential prey. But the state has changed a lot since gray wolves had the run of the place in the 1800s. There is little open space, and the climate is drastically altered; if wolves return, their ecological role will be very different.

These are just some of the beautiful murals adorn the outside of the labs at Schmahl Science headquarters.

Let’s say you’re a student who wants to do a biology experiment for a science fair. Maybe you want to figure out how a certain cancer works or engineer a drought-resistant plant or any other sort of higher level experiment. How in the world do you get started and then do the necessary experiments?

If you know a biologist, then you can get them to help you. Unfortunately most folks don’t know any scientists let alone biologists. What interested people usually have to do is start cold-calling institutions and universities, hoping to find someone willing to help. This is rarely successful.

But if you’re in the South Bay, there is another possibility – Schmahl Science. For around $40/hour, you can do your experiment with the help of a mentor in the lab facilities at Schmahl Science headquarters.

The price is a bargain by science standards but still ain’t cheap. For example, a cancer project can end up costing upwards of $3000! There are scholarships available and there is a sliding scale based on family income, but it will still definitely cost you. However, if you’re interested in doing a top notch science fair project and learning more about science as a career, you can’t beat it.

I recently had the chance to take a tour of the facilities and chat with the executive director, Belinda Schmahl. My first impression of the place was that it was a bit ramshackle. It seemed to have been cobbled together from various spare parts into a Frankenstein sort of creation. This is because it was.

They are able to keep prices so low (and really, they are low) by using other people’s castoffs in a location that is a bit off the beaten track. What it lacks in finish, though, it more than makes up for in personnel.

I was incredibly impressed with the mentors I spoke with. They were knowledgeable and very excited about their students’ projects. And I can see why.

One student I saw there was working on a biochemical experiment to test how well various sunscreens actually protect people from harmful ultraviolet light. One mentor told me about a successful experiment a student had done to generate electricity from bay mudflats. Another mentor told me about a student’s project that was exploring how houseflies were able to fly. Still another told me about a student’s project on the effects of the herbicide RoundUp on certain bacteria rice needs to grow. And so on.

Of the 100 students mentored for the Synopsys science fair last year, 78 received some sort of award. This gives you some idea as to the quality of the work and the guidance each student receives.

These are incredibly interesting and important experiments that the students would not be able to do on their own. What a great service this organization provides for the community. I hope one day it can be cloned over and over again so more students can experience the thrill and excitement of science.

More information on the program

Recent winners of the Synopsys Science Fair. Wow.

Do-it-yourself biology at Biocurious. Photo credit: Maria Chavez.

Let’s say you want to do a little “do-it-yourself” biological tinkering. Maybe you have an idea to make bacteria that can sense or even break down mercury in the environment. Or you want to attract funding for your start up with a few choice experiments. Or you just always wanted to do some biology. Where can you turn?

For people like me, it’s easy. I work for Stanford’s Department of Genetics and so if I were so inclined, I’d have access to the labs there. But this obviously isn’t a typical situation.

For everyone else (at least here in the Bay Area), there is an organization called Biocurious. They are an open lab located in Sunnyvale where you can go and do some biology experiments.

For a monthly fee (currently around $100/month for a year subscription) they provide the equipment, a lab bench and office space. You also get free classes from experts to help you get started.

This lab space is great for folks with some previous lab experience and/or who have an idea of their own they’d like to get started on. The equipment is all there for them to get started and they even get 15% discounts on any reagents they need. Stuff like restriction enzymes, Taq polymerase, nucleotides, etc.

But at least for right now, the space/concept isn’t as useful for the uninitiated. If you just want to come and play, it can be hard to know what to do. Sort of like wanting to design a mobile app but having no experience and having never used one!

One thought I had was maybe membership can come with an optional, relatively simple project that can be done to get the member’s feet wet. Maybe using the mixable and matchable bits of DNA from BioBricks to create a unique, artificial gene. That way the member could create something new but not have it be some cookbook, high school experiment.

This was just one idea off the top of my head. The folks at Biocurious know this is a problem and are brainstorming solutions. Can you think of ways that might help a newbie get started? What would it take to entice you to come join the fun?

Great interview with Eri Gentry, founder of Biocurious

Animals are doing surprisingly well in the radioactive areas around Chernobyl.

Imagine people’s worst fears are realized and the nuclear power plant at Diablo Canyon here in California has a Chernobyl-style meltdown. The effects on people are obvious: high rates of thyroid and other cancers, permanent resettlement elsewhere, increased rates of birth defects and so on. But as the area around Chernobyl is showing, the effects on the environment may be more subtle.

Over the break I watched a Nature special called, "Radioactive Wolves". This is a documentary about wildlife in a radioactive exclusion zone around Chernobyl.

Even though the area around Chernobyl is still so contaminated that humans can only go in for limited amounts of time, the wildlife appears to be doing surprisingly well. Birth defects are higher than in surrounding areas but life is thriving. Wolves are doing great, beavers have returned and everything looks hunky dory.

This seemed strange to me. I would think that so much radiation should be having pretty severe effects on these animals. And as noted in this in this NIH study, for certain individuals it definitely is.

The difference is in perspective. For the individual, the area around Chernobyl is terrible. Your kids have a higher rate of being stillborn or having birth defects, you have a much higher rate of developing various cancers, and so on. But for the species as a whole, things aren’t so bad. The higher background radiation appears to hardly be affecting their numbers at all.

Now this isn’t to say that the initial fallout wasn’t catastrophic to wildlife. It was. Untold numbers of animals died a terrible death in Chernobyl’s aftermath.

For the lucky survivors and new immigrants, though, Chernobyl is a different story. It is a chance to live a life without human interference. At least for now it looks like the high background radiation is preferable to man for these animals.

It is important that scientists keep studying this ecosystem though. The DNA of the animals in this area are under constant attack from the radiation. There may come a tipping point where the genetic burden becomes too high and populations start to crash. We’ll have to wait and see.

Additional Reading: NY Times Review of Radioactive Wolves

Do you have a unique voice that sets you apart from the crowd? Contribute your stories to QUEST!

KQED QUEST is looking to add new voices to our blog, which already offers commentary from our producers, reporters, and local writers from our partner institutions at Chabot Space & Science Center and The Tech Museum.

We're looking to include folks who are actively involved in the science, environment and nature blogging community – e.g. have a blog, guest post on others' site, and comment / participate in relevant discussions. And we're looking locally. Our blog has a strong SF Bay Area focus, though we do occasionally cover and/or perform analysis on how this stuff elsewhere that affects the Bay Area.

What we cover

QUEST’s geographic coverage is from Mendocino to Monterey and from Sacramento to Santa Clara, and generally covers 9 content areas: astronomy, biology, chemistry, engineering, environment, geology, health, physics and weather.

Requirements

• Original posts, 3-500 words with at least 1 image. Schedule determined on availability, but weekly or bi-monthly is preferred.
• Posts should relate back to at least one of our 9 themes for the program: Astronomy, Chemistry, Engineering, Physics, Weather, Geology, Biology, Environment, Health.
• Topic should be something about which you have some expertise and/or passion.
• A unique voice and ability to follow our QUEST writing guidelines (see below).
• Experience with WordPress or similar blogging platform.
• Willingness to occasionally be assigned a post topic by the editor as current events dictate.
• Respect for copyright and fair use.

Would I get paid?

Yes – we offer a small stipend on a per post basis.

Alrighty, then. How do I apply?

Email us a note and bio to questeditor@kqed.org explaining what you'd like to write for us. Please also include some links to relevant blogs you admire, and/or participate in, and why. Send us a writing sample or two (links are fine), and we'll review it in the next couple weeks. Last day to submit is February 1st. Our hope is to bring aboard a few new bloggers by mid-February.

Some beats we're interested in

Although we want to hear from a wide range of writers, here are a few coverage areas we're keen on in particular:

• Bay ecology background and issues
• Science education
• Silicon Valley / engineering innovations
• Hacks, DIY, and hands-on science activities
• Hiking and outdoors (with a science focus)
• Food science
• Convergence of art & science
• Nature & science photography

Writing Guidelines

(As laid out by our managing editor, Paul Rogers)

Why does my grandmother care? A key requirement of QUEST bloggers will be to explain scientific and environmental issues in a way that the general public can understand. Our audience is mostly made up of people who aren’t scientists or environmental activists. Posts should explain why the topics they are writing about are relevant to Bay Area residents.

Get to the point. Studies have shown that readers spend only a minute or two on most web sites before moving on. The average reader reads about 200 words a minute. Write tight, and lively. Keep it interesting and informative.

Avoid jargon. The purpose of good writing is to communicate clearly. Don’t use complex, esoteric scientific terms. Instead of saying "non-point source pollution," say "polluted runoff." Instead of "extravehicular activity," say “space walk.”

Be personal. Relate personal experiences. Speak in the first person. Tell them where you saw the blue herons or which movie best depicts what a real moon base might look like. Find your own voice and write in a compelling, approachable way.

Be passionate. Write about subjects and topics that you care about. Please don’t feel you have to stick to a script or formula. Express yourself.

Drive traffic to the blog. Place a link in your correspondence and comments to the blog. Mention it on other web forums.

Write for the bigger picture. Don’t view the blog as a place just to promote your institution or pet cause. Keep in mind your audience is made up of a wide diversity of people, with wide interests.

Speak your mind, but check your facts. Or your audience will do it for you with painful results.

Know your fellow bloggers. You'll be part of a vibrant community with fresh ideas and discussions nearly every day. Don't be afraid to comment on their posts, or link to their entries. Have fun with it! Dreary bloggers or insufferable policy wonks need not apply.

Swapping scions at a California Rare Fruit Growers Scion Exchange. Photo: terriem.

Is your new year’s resolution to eat more fruits and veggies? Or eat more local produce? You can do both at once by growing your own fruit—you can’t get more local than fruit you harvest in your own backyard. Start by going to a scion exchange, where local rare fruit enthusiasts take cuttings from their fruit trees and swap them for other varietals.

The California Rare Fruit Growers (CRFG) hold these exchanges in the winter, when fruit trees are dormant. It’s a good time to clip the pencil-thin branches that have grown in the past year—called the scion—and graft these branches onto other plants. The Golden Gate Chapter of the CRFG is holding its annual scion exchange on Saturday, January 21 at Laney College in Oakland. Check this list to find your local chapter and its upcoming scion exchange.

Before you go to the exchange, make a wish list of the types of fruit trees you want to acquire. (The cuttings are free—donated by individuals—but the organization usually requests a small donation. The Golden Gate Chapter requests $4, but they note that no one is turned away for lack of funds.) Base your list on the types of fruit you like to eat, and the climate where you live.

An important measure of climate is the number of chill hours an area receives: the cumulative number of hours throughout the winter when the temperature is between 32 and 45 degrees Fahrenheit. Find out the number of chill hours for your area, so you know what kinds of fruit trees to choose. For example, the Oakland Hills, where I live, get about 400 chill hours. According to the Making the Best of the Scion Exchange guide from the Golden Gate Chapter of the CRFG, the best trees for my cool summers and mild winters are lemons and something called feijoa (a.k.a. the guavasteen). It isn’t cold enough for apples, nor is it warm enough for grapes. Also think about your yard’s aspect: if you are on a north-facing slope, you’ll probably get more chill hours than if you’re on a south-facing hillside, which tends to get more sun.

Once you’ve made your list and acquired the scions you want at a scion exchange, the next step is to graft these on to existing plants. You can use rootstock, which are young plants that are grown for grafting. Or you can graft onto an established tree that is already growing in your backyard, a practice known as top working. Some plants can be grafted only onto the same kind of tree—like apples to apples, quince to quince. Others can be grafted onto other types of trees—for example, pears can be grafted onto quince trees (if you happen to have one of those in your backyard). You can get rootstocks at the scion exchange, and (more importantly) advice on how to graft; there are several grafting workshops at the Golden Gate event on January 21.

One more thing to think about as you make your wish list: if you’re planning to grow multiple trees, you want to stagger your harvest throughout the year, so you aren’t inundated with fruit all at once. Or, if you’re planning to make jam or to dry your fruit to save it for later, maybe a bountiful harvest is okay. Here’s to a fruit-filled 2012!

For now, sulfites are able to kill the yeast that might spoil this wine.

Wine sometimes tastes a bit funky because it was contaminated during fermentation with a yeast called Brettanomyces bruxellensis. This yeast can give wine a variety of interesting flavors like “…horse sweat, Band Aids, barnyard, and burnt plastic…”

Winemakers usually keep this from happening by killing off the yeast with those dreaded sulfites. But for awhile now, people in the know have been worrying about the emergence of a sulfite-resistant form of this yeast. And this is a well-founded fear.

Yeast, like bacteria, are fast growing microorganisms with lots of variation in their DNA. If you hit a population like this with something that kills them (like sulfites for B. bruxellensis or antibiotics for bacteria), some small percentage are probably going to be resistant. These resistant strains can then grow and replace the sensitive ones. The end result is sulfite-resistant yeast ruining our wines.

To try to head off this problem, a group of scientists in Australia has figured out this yeast’s DNA. The hope is that scientists will be able to use this data to determine how B. bruxellensis might evolve into a more resistant form.

Note that despite much trumpeting online, they haven’t really solved any problems with this knowledge yet. They have merely created the tool that might let them solve a potential future problem. And given how cheap and easy DNA sequencing is these days, it isn’t necessarily even an impressive feat of technological prowess.

Still, it may one day prove useful in allowing winemakers to more quickly defeat a sulfite-resistant strain. Which can only be a good thing for wine making.

I don’t want to end this before saying a nice word or two about B. bruxellensis. This yeast can spoil wines but it isn’t all bad.

For example, it gives Belgian beers their special taste. And some winemakers actively seek it to give their wine a bit of a “brett” taste.

Still, a sulfite-resistant form would definitely be a bad thing for most winemakers. So scientists should definitely stay vigilant and be ready to come up with quick solutions using this new tool (and whatever other ones they can find) when sulfite-resistant B. bruxellensis begin to appear.

The new Mercury and Air Toxic Standards announced by EPA administrator Lisa Jackson on December 21st require the electrical industry to limit stack emissions of mercury, arsenic and other toxic pollutants that originate from coal and oil-fired power plants and end up in America's air, water and food. Power plants are the largest source of mercury emissions at around 50 tons of mercury pollution annually. Because the particles are heavier than air, the mercury eventually falls back down and is deposited in rivers, lakes and oceans where it is converted into a more toxic form called methylmercury. This builds up in the food chain, meaning that fish at the top, such as striped bass, blue fin tuna and shark, carry the highest levels of the toxin.

The EPA estimates that 11,000 premature deaths and 130,000 cases of aggravated asthma among children annually by 2016 will be prevented, as well as other health benefits. Women, children and the developing fetus are most at risk for serious health problems resulting from mercury exposure. Between 300,000 and 600,000 of the 4 million babies born in the U.S. each year are exposed to significant amounts of the neurotoxin while in the womb.

Using scrubbers and other well-demonstrated technology, the rule requires power companies install equipment or shut down old plants by 2014 with the possibility of an extension into a fourth year. Seventeen states have already required the industry to apply the clean technology. These older US plants, operating mostly in the Midwest and East, can affect our Bay Area waterways and we will benefit from the new rule. However, most of the mercury in the San Francisco Bay enters from spills, the air, or water runoff from land from natural sources and historical mining.

Mercury levels will remain high in many species of San Francisco Bay and some ocean fish as well as other toxins like PCBs. The California Office of Environmental Health and Hazard Assessment (OEHHA) monitored contaminants in chemical contaminants in fish from the San Francisco Bay.

While the EPA rule is good news for Americans, we must be cautious about what fish and how much fish we consume. Some fish from San Francisco Bay like rockfish and smelt are low in mercury and can be safely eaten. Others like wild king salmon are high in Omega-3s that have been demonstrated to be beneficial to human health. Others like sharks, striped bass and other top predators like swordfish and tuna bio-concentrate mercury and should be avoided, especially by women 18-45 and children under 7 years. The point is to ask where your fish is coming from, how was it caught and how much can you eat. A mercury calculator on the "Got Mercury?" website allows one to calculate how much mercury they are consuming and if it exceeds advisory guidelines produced by the EPA.

The "Got Mercury" Campaign, a project of the Turtle Island Restoration network based in Marin County, is building awareness about toxic mercury in commonly eaten seafood. To reduce risk from mercury exposure, "Got Mercury" is asking the government to increase health advisories and reduce action levels for mercury in fish. The program is also petitioning the FDA to lower the legal mercury action level from 1 part per million (ppm) to 0.5 ppm to be in line with the Environmental Protection Agency’s mercury standards for recreationally caught fish and to require seafood sellers to post mercury in fish warning signs.

The next time you go to the beach, whether at the ocean or beside a river, take a closer look at the sand and think about the stories those grains can tell!

Sand . . . we play in it, we stroll on it, we make castles out of it, but what do we really know about it?

Most people use the term “sand” to refer to loose material on a beach, but sand is actually a grain size measurement used by geologists to describe sediments varying in size from about 1/16 mm to 2 mm in diameter. Sand can be found not only along ocean beaches, but along flowing rivers and beside land-locked lakes.

Mineral and volcanic sands are terrigenous, meaning that they come from the land. Mineral sands start as mountains and boulders and are gradually broken into smaller and smaller particles by weathering and erosion. Being alternately heated and cooled through the seasons, rolling and tumbling around in mountain streams and rivers, rocks are broken apart by the water’s movement. The black sand beaches of some islands (e.g. Hawai’i) are volcanic in origin. Lava rocks, chunks of cooled molten lava, are broken down into sand over time by physical and chemical weathering.

Some sand is biogenous, meaning that it comes from living things, such as mollusk shells and corals. The energy from water breaks shells down into tiny pieces that eventually are washed onto beaches. Parrotfish in the tropics use their teeth to scrape off and grind down bits of coral reefs; the undigested particles pass through the fishes’ digestive systems and end up as sand on tropical beaches!

If you examine the beauty of beach sand with a magnifying glass, the shape, size, and color of the sand grains can tell many stories.

Shape indicates the age of sand grains. Different materials break down at different rates. For example, quartz is very sturdy and takes longer to become sand than the calcium carbonate material of mollusk shells. Younger sand has sharp and angled edges; it needs time and wave action to become rounded. Sand particles that are smooth and well-rounded are evidence that they have been rolled around for awhile.

Wave action is the story told with grain size. The story is simple: small waves move small sand grains around; large waves move large grains. In addition, Aeolian transport, or sand movement driven by winds, shifts the sand around on the beach, shaping and reshaping, covering and uncovering.

Color offers evidence for source materials – sand particles that are clear, tan, gray, or brown might be quartz or feldspar, black or gray particles could be ilmenite (titanium oxide) or magnetite (iron oxide); garnets are red, mica is silvery black or gray, and shells are purple, white, black, or brown.
The chorus from the song “Mountain in my Hand” (on the Only One Ocean CD by the Banana Slug String Band) explains it best:

“I’ve got a mountain in my hand from the rain-washed land; down by the sea now is where I stand, with this mountain in my hand trying to understand; Oh, oh, wonderful sand.”

Additional Links

• Sea Grant North Carolina