"Attack of the Alien Invaders," produced by WVIZ/PBS, was first created as an educational series called "LSI: Life Science Investigation."

Lake Erie is considered to be the most productive of all five of the Great Lakes.Within its waters are diverse and interdependent plants and animals that make up an intricate web of life. Mostly due to human carelessness, the lake has become home to an increasing number of non-native plants, animals, and micro-organisms which threaten the balance of the entire ecosystem.

In the WVIZ/PBS program, Attack of the Alien Invaders, Dante Centuori, Director of Creative Productions at the Great Lakes Science Center in Cleveland, Ohio, traveled in and around Lake Erie visiting with scientists and government officials who are investigating Lake Erie’s ecosystem, the challenges it has faced in the past, as well as those it may face in the future. Of particular interest was one of the biggest potential threats to the lake- a voracious invasive species collectively called “Asian carp.”

Bighead carp (Hypophthalmichthys nobilis) and Silver carp (Hypophthalmichthys molitrix) were first introduced to the U.S. in the 1970s as a chemical-free and “environmentally friendly” way of cleaning up algae in southern fish farms and water treatment plants. During the Mississippi River floods of the early 1990s, these fish escaped into “The Big River” and its tributaries. Since then, these big, hungry, and prolific fish have made their way north all the way up to the back door of the Great Lakes. If they enter the Great Lakes, it is feared that these fish will continue on to Lake Erie where they could further disrupt the Great Lakes’ most productive ecosystem, with unknown long-term consequences.

John Hageman from Ohio State's Stone Laboratory shows Dante Centuori an invasive Silver Carp.

Dante first visited Stone Laboratory, a research facility located in the Western Basin of Lake Erie in Put-in-Bay, Ohio. There, he met John Hageman who displayed, and dissected a Silver carp; revealing an anatomical structure that makes these fish particularly threatening to the food energy balance so important to Lake Erie’s native inhabitants. Dante then accompanied another Stone Lab researcher on a good old fashioned Lake Erie “fish trawl” where he came across many of the lake’s native and invasive species– such as the omnipresent zebra mussel and the abundant quagga mussel, two detrimental invasives brought in to the Great Lakes by the ballast water of ocean-going vessels.

Dante continued on to Old Woman Creek, a national research center and fresh water estuary in nearby Huron, Ohio, where he encountered some frisky common carp (Cyprinus carpio) whose behavior may help scientists predict what may happen to Ohio’s interior rivers and streams, if their distant relatives from the east choose to join them. Next, he returned to Stone Lab to investigate how the Bighead and Silver carp have influenced and impacted the native species of the Mississippi and Illinois River ecosystems. He next traveled to Lake Erie’s Central Basin- to Cleveland, Ohio for a rendezvous with a federal employee who explained how Asian carp are being monitored and controlled in one of the most probable points of entry into the Great Lakes, Chicago’s Shipping and Sanitary Canal at the southern end of Lake Michigan.

Lastly, Dante returned to Put-In-Bay where he talked with Jeff Tyson of the Ohio Department of Natural Resources, who described the management techniques used to control one of the harmful invasive species in Lake Erie; the Sea Lamprey. Could techniques similar to those used to control the Lamprey be applied in the event of an Asian carp invasion? What other plans are in place if these strange and dangerous "jumping fish" make it to Lake Erie? If they do, and these strategies don’t work, what’s next? Even though each expert interviewed had his or her own theory, in the end, they all agreed that it is not a scenario that they’d want to see play out.

Before Attack of the Alien Invaders was broadcasted to a general audience in January of 2011, WVIZ Education produced “LSI: Life Science Investigation,” a multi-media resource created for the classroom. Scott Barber, a teacher in Berea, Ohio, explained how this “fish story,” presented as an interactive mystery, and accompanying classroom resources on the web, has helped his students learn core life science concepts.

Climate change and invasive species threaten Lake Tahoe just as restoration funding dwindles. (Photo: Lauren Sommer)

Over the last 15 years, more than a billion dollars has been spent to protect Lake Tahoe's clear waters from runoff and erosion. Now, new threats to lake's clarity are emerging, just as restoration funding is drying up.

Researchers from UC Davis are hot on the trail of one of those threats. On a recent late summer morning, Katie Webb and a team from UC Davis's Tahoe Environmental Research Center went looking for it on a boat near South Lake Tahoe.

"So what we're looking for is a metal clam corral," Webb says, pulling on her scuba gear. The "clam corral" is a wire basket that holds clams living on the lake bottom. Webb swims down to it and attaches a rope, so the team can pull it on board.

The clams inside are Asian clams, an invasive species. They were not a welcome visitor when they were discovered in Lake Tahoe in 2002. Webb and her team are monitoring these corralled clams to see how fast the population is growing.

"So you can see this individual is number 11," she says, pointing to a tiny number super-glued on its shell. They use the numbers to track individuals over time. "We can see how much they've grown since we checked them in February and it should be a lot. They grow a lot in the summertime," Webb says.

"What they do is somewhat disturbing," says Geoff Schladow, director of the Tahoe Environmental Research Center. Asian clams filter massive amounts of lake water and that's where the problem starts.

"Of everything they filter, they consume about 10 percent of it and 90 percent they excrete. So their excretions are like these huge nutrient bombs," Schladow says.

UC Davis researcher Katie Webb holds an Asian clam from their population study. (Photo: Lauren Sommer)

With thousands of clams per square meter in some parts of the lake, their "nutrient bombs" help create algae blooms.

"So you have this bright green, stringy algae, sort of clinging to the bottom, a few tens of yards from the beach. People would be astounded to see this cause it looks like any place but Tahoe," he says.

In the face of this invasion, a team from UC Davis has been experimenting with rubber mats that suffocate Asian clams on the lake bottom. So far, the treatment looks promising.

Tahoe Basin Building Boom

Keeping the lake blue – and not green – has been a rallying cry for both environmental groups and Tahoe's tourism industry. Forty years ago, scientists could see 100 feet into the lake. Today, the clarity has decreased significantly to 64 feet.

"We're essentially like a bowl and what happens on the land affects the water," says Julie Regan of the Tahoe Regional Planning Agency. The agency oversees development on both the California and Nevada sides.

"What happened on the land in the 50s, 60s and 70s is that we had a lot of development – rampant overdevelopment," she says. Tahoe hosted 1960 Winter Olympics at Squaw Valley. Casinos went up. Building was booming. And soon, the region had a runoff problem.

"It's driveways. It's houses. What you cover on the land then interferes with the soils ability to filter runoff. That's what's causing clarity loss," says Regan.

Over the past 15 years, local agencies have tried to stop this decline with $1.5 billion of federal, state and local money. They've preserved open space and built projects to control erosion and filter runoff.

"In 2008 we got the news from the scientific community that we had stopped the slide and decline of lake clarity. That was great news," says Regan.

Scientists See Climate Change Impacts

In 2010, however, researchers at UC Davis found the second worst clarity level ever recorded. Geoff Schladow says runoff isn't the only culprit.

"What we've had just in the last few years is this explosion, this large increase in algae and they seem to be concentrated right near the surface," says Schladow.

These algae are invisible to the eye, but they're the right size to make the water look cloudier. Normally, they're competing with large algae near the surface. But Schladow says that's changing. Algae are heavier than water, so they gradually sink.

"The algae in the past tended to be mixed by the wind every few days. So if you're a large algae and you sank down 50 or 100 feet, you could be brought up again into the light by mixing."

Recently, the lake hasn't been mixing as much. The reason, Schladow thinks, is that the surface waters of the lake have gotten warmer with climate change. Warmer water is lighter than the cold, dense water at the bottom of the lake. So it's little bit like oil and water. The layers of the lake are more resistant to mixing.

"Now when we have less mixing, the large algae sink out. All we're left with are the small ones. And so their numbers are going up," says Schladow.

After decades of conservation work to reduce runoff, a lot of people are disappointed to see climate change posing a new threat to Lake Tahoe's clarity.

Schladow thinks it's not hopeless. "It's a call to redouble what we're doing, not to give up and walk away. It's now needed not just to restore clarity but to ward off what may be some pretty uncomfortable and disturbing features of climate change."

Restoration Funds Running Out

After an unprecedented influx of restoration funding, resources are now running low. Senator Dianne Feinstein introduced the Lake Tahoe Restoration Act of 2011 in Congress to authorize more, but has said she's not optimistic about getting it passed.

"We know the funding picture could potentially be bleak, so we're looking to any strategy that we can to keep this momentum going in terms of restoration," says Julie Regan of TRPA.

On top of that, Nevada is threatening to end its forty-year partnership with California by pulling out of the Tahoe Regional Planning Agency, unless concessions are made about its voting power on new development. Regan says it's just one more challenge that will make the next few years a critical time for Lake Tahoe's future.

Water forecasting could be thrown off by a changing climate. Credit: Craig Miller

The severe flooding on the Mississippi River has left a lot of damage in its wake. It's an extreme event that government and insurance companies try to plan for by predicting the risk. But climate change is throwing a wrench in those calculations.

Most of us don't think about risk. We think about randomness. That's illustrated by a scene in the 1982 movie, "The World According to Garp", where Robin Williams is shopping for a new house with his wife. They're standing in front of one home when…a plane crashes into it.

Despite the crash, the Robin Williams character agrees to buy the house saying, "It's been pre-disastered! We'll be safe here."

That may not be a typical reaction, but climatologist Kelly Redmond says it reveals a lot about how we think about risk. "It has to do with how we describe rare things. We spend societally an enormous amount of resources and time and attention guarding against the very worst possibilities."

Listen to the QUEST radio story Insuring for Extreme Weather

You've probably heard of the "100-year flood." That's a flood so severe that it has a one in one hundred chance of happening every year. But how do we know that?

"About the only way we can get at how rare a rare thing is is by looking at a past record," says Redmond. So for floods, government agencies look into the historical record to see when floods happened in the past. They use that record to predict future flood risk.

But this relies on a very basic assumption. According to Redmond, the assumption is that the statistics of the future will look like the statistics of the past.

There's a fancy term for this – it's called stationarity. But there's a problem.

"What we don't know but what we suspect with changes in climate is that those statistics, especially about rare things, may change," says Redmond.

The US is already warming. Climate models show that western states could see more extreme weather as the climate continues to change. So, Redmond says, chances are good the future won't look like the recent past.

Jeanine Jones of the California Department Water of Resources agrees, saying "a lot of California's existing infrastructure was designed on assumptions that are no longer valid."

History of Water Forecasting in the West

Jones says using the past as a guide for the future is a huge part of water planning and building codes. The idea was first adopted in the 1940s and 50s, when dams and infrastructure were built at record speed in western states.

"Congress was looking at all these water development plans coming in from the Corps of Engineers and the Bureau of Reclamation and wanting a common standard to compare all the projects," says Jones.

So they forecasted flood risk and water supply by looking at historical data. "But they had very short data records. Maybe they only measured records of 20 years, 50 years. And that's not really very long," Jones says.

Today, everything from building codes to home insurance is based on this short window of data. And so is another critical forecast.

During the winter, surveyors measure the Sierra Nevada snow pack every month, so they can crunch the numbers and predict the year's water supply.

"It is very widely used by reservoir operators, by water agencies, by farmers who are looking at what are my chances for having a full water supply," says Jones.

But climate models show that more precipitation will fall as rain in California, instead of snow. And that means spring runoff could behave very differently. "At some point, conditions will change enough that we've reached a tipping point where those statistical approaches really aren't valid anymore," Jones says.

An accurate water forecast is crucial to California's economy. So Jones says water officials are looking at using computer models to forecast spring runoff.

But when it comes to updating flood risk and building codes to reflect climate change, Kelly Redmond says that could take decades. "We have to get a buy in from the engineering community, the city planners. Because there's so much expense to goes into building a bridge or a culvert or a building."

A New Breed of Insurance Company

There is one industry that's taking note of climate change – insurance.

"The increased variability in climate is going to start to dramatically affect the profits of corporations worldwide," says David Friedberg, CEO of San Francisco-based Weatherbill.

Weatherbill is something of a next generation insurance company. They start with computer models that simulate weather and climate patterns. "We then use those sorts of models to determine what sort of price we should charge for certain weather events occurring," says Friedberg.

Weatherbill works mostly with farmers, insuring them against extreme weather for between 40 and 400 dollars an acre. "There's a range of things that can occur and that range is certainly widening. And as a result we should start to charge more for those sorts of events when we're insuring them."

Friedberg says this kind of insurance makes sense to a lot of farmers they work with, who are already noticing changing weather patterns. Investor Vinod Kholsa and Google have also noticed and put millions into the company. They're betting new software will be the answer when today's methods no longer work.

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It's been a harsh winter across the US. Snow has blanketed the Sierra Nevada, where the snowpack is well above normal. Lots of snow means good skiing, but it also means an increased danger of avalanches.

Avalanches aren't something most skiers and snowboarders have to think about. That's because ski areas take preventative action.

On the backside of Squaw Valley Ski Resort, two ski patrollers drop into a black diamond run known as Granite Chief. Below them are mounds of fresh, untouched powder – more than seven feet deep.

The patrollers are throwing explosive charges onto the slopes to trigger smaller, less dangerous avalanches. Booms ring out across the mountain.

Listen to the QUEST radio story The Science of Snow

"The Sierras are known for getting tons of snow really quick," says Will Paden, the avalanche forecaster at Squaw Valley Ski Resort. "We're constantly trying to start the avalanches so that we don't let the snow pack build up to be too deep."

Paden says on a day like today, they'll use more than a thousand pounds of explosives to make the ski area safe. But the job isn't over when the snow stops falling. The snowpack is constantly changing.

"One day could be perfect powder and then that afternoon the wind can pick up and put wind crust on top of that perfect powder and make it difficult skiing," says Paden.

Avalanche forecasting is even more technical. "We had a lot of riming in this snow and some graupel events."

To translate that, you have to go inside the snowpack.

On a slope outside of Truckee, Brandon Schwartz uses a shovel to cut a cross-section in the snow. As a forecaster with the non-profit Sierra Avalanche Center, Schwartz has dug thousands of avalanche pits like this one.

An avalanche near Echo Summit in Lake Tahoe.
Credit: Travis Feist"We can feel the different hardness of all the layers that have formed in the snow that's fallen over the last two to three days," says Schwartz.

Schwartz is looking for weak layers of snow, which is where avalanches begin. He pulls out a saw and slices through the snow to isolate a one foot wide column. Then he places his shovel on top. "And we'll just start to load on top of it first with ten taps just from my wrist, just from lifting my wrist and letting gravity pull my hand down."

Those taps simulate what a little weight would do to the snowpack, either from more snow falling or from a skier.

Schwartz points to where the snowpack has broken away along a straight line. "So we got a pretty significant crack all the way across the column here. Definitely a difference in strength there and that's what makes up the layers of snow pack and when we have these layers of different characteristics then we start to get some of the ingredients for a slab avalanche."

Schwartz and his team travel into the backcountry every day to assess the avalanche danger in the Tahoe region. Of the 36 people who died in avalanches across the United States last winter, almost all of them were in the backcountry. A large storm like this one means today the danger is high.

But what makes some snow weaker than other snow?

"Once we have snow on the ground, a whole bunch of really interesting things happen. You think of the snow as being rather static, but it's not at all," says Jeff Dozier, an environmental scientist at the University of California-Santa Barbara who studies how snow impacts California's water supply.

Dozier says to understand what's happening, you have go all the way down to the level of a snowflake.

Check out the different types of snow crystals, as seen under an electron microscope:

Once the snow falls, the snow crystals will start to stick together. As they sit there, the crystals grow rounder and bond together. "And if you shovel snow, you see this. If you shovel snow when it's new, you can stick the shovel in the snow and you can lift it. You shovel snow when it's old, it's hard to break that block of snow loose from its neighbor."

When a lot of snow falls quickly like it does in the Sierras, this bonding process may not happen fast enough to support the snowpack, which leads to avalanches. The warmer a snowpack is, the faster it bonds. But if it's colder, sometimes a different kind of crystal grows.

"Typically the temperature at the base of the snowpack – this is gonna be around zero degrees C. But on a very cold night, the temperature at the surface say might be -20 degrees C," says Dozier.

That difference in temperature can create another shape of crystal – a faceted crystal. "They're sort of angular. They don't bond together very well."

These crystals look like grains of sugar and they create weak layers deep in the snowpack. A better understanding of snow crystals could help avalanche forecasters. Dozier says it could also help water managers trying to anticipate the snowpack melt in the spring, an event that's critical to the state's water supply.

Avalanche forecaster Brandon Schwartz in the field:

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Click here for a larger version of the Nile Delta.

The Sacramento-San Joaquin Delta has this classic, triangular shape but with a major caveat — it’s inverted. That is, instead of the delta splitting into numerous channels in a downstream direction, it is characterized by numerous channels coming together in a downstream direction. The geologic history of the greater Bay Area helps explain this rather unique delta geometry. Unlike the Nile, Amazon, Mississippi, and other major river systems, the location where the Sacramento-San Joaquin rivers meet sea level is: (1) well inland of the coast and (2) strongly controlled by the topography of the region.

The Sacramento-San Joaquin Delta is known as a bay-head delta, which is when a delta forms at the head of a large estuary like the San Francisco Bay. When sea level was much lower during the last ice age the river met the sea at the position of the Farallon Islands. As sea level rose and the valleys that are now the Bay flooded, the river mouth moved inland to its current position. The complex topography of the Bay Area — a result of active faulting associated with the San Andreas, Hayward, and other faults — has forced the channels in the delta to come together at Carquinez Strait.

Future sea-level rise will affect the delta region, especially Suisun and Grizzly Bays, significantly. Even a relatively small rise will change the character of these wetland areas. Further east, near Antioch and Lodi, the delta is actively subsiding (sinking), which could exacerbate the negative effects of a rising sea level even more.

Images: (1) Nile River Delta; credit: Wikipedia, (2) Basemap from FlashEarth, annotation by me.

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Satellite image of the western United States, taken on Thanksgiving Day. Image: NASA.

The defining sign of a La Niña is cooler-than-average sea surface temperatures in the Pacific Ocean, near the equator. Cooler water evaporates less than warmer water, so there is less moisture in the air. This means that during a La Niña, there is less precipitation in some areas, like California and the southern United States. Other areas, like the Pacific Northwest, get more precipitation during a La Niña. (Book your winter ski trip strategically!)

Sea surface temperature anomalies on November 25, 2010. The equatorial Pacific is cooler than usual (note the blue color), a characteristic of a La Nina event. Image: NOAA.La Niña also affects air temperature. During a La Niña, the South is typically warmer, while Southern California and the Pacific Northwest are cooler. You can see climate predictions for the next three months, from the National Weather Service Climate Prediction Center.

A La Niña is basically the opposite of an El Niño. El Niños are characterized by warmer-than-average sea surface temperatures in the equatorial Pacific. This happens when the atmospheric pressure system gets a bit out of whack. Usually there is high pressure over the Pacific Ocean and low pressure over the Indian Ocean—picture a see-saw anchored over New Zealand, with the heavy kid sitting on the end over Indonesia. For reasons we don’t quite understand, sometimes the see-saw tilts the other way—now the heavy kid is sitting in the southeastern Pacific, and the kid on the Indonesian side is way up in the air.

This swap in atmospheric pressure has quite a few consequences. The trade winds (which typically blow across the Pacific from the east to the west) get weaker. The water that the trade winds usually push westward instead piles up and moves east. This water is warm, and it evaporates, causing more rainfall along the west coast of South America. Meanwhile, places like Indonesia and Australia get less rainfall, along with drought and fire.

The weakening of the trade winds and westward flow of ocean currents in the Pacific has a second effect. Under non-El Niño circumstances, the trade winds carry the top layer of water to the west, and so water from deeper in the ocean moves up to take its place. This is called upwelling. The water from deep in the ocean is cold and full of nutrients, and it drives the fisheries along the coast of Chile and Peru. Without the trade winds and the upwelling, fisheries crash. A strong El Niño has big economic impacts, not all of which are negative; some agricultural areas are benefited by the extra rainfall, and people in places with unusually warm weather can save on heating bills. Of course, La Niña events have economic impacts too.

As scientists learn more about predicting the climate during El Niños and La Niñas, we can plan accordingly and mitigate the economic impacts of these events. My comment about planning your ski vacation according to this year’s La Niña was a little bit serious! Rainfall predictions based on El Niño and La Niña models can help farmers decide which crops to plant. And, here in drought-prone California, La Niña precipitation predictions are influencing water allocation decisions for the coming year.

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Artist's rendering of the LCROSS spacecraft and its upper stage Centaur rocket. Image courtesy of NASA.

Reported for KQEDnews.org.

Last year, NASA scientists in Mountain View made international headlines when they crashed a rocket into a permanently shadowed crater on the moon's south pole and announced they had found water there.

On Thursday, they unveiled new findings about the amount of water on the moon and a "treasure trove" of gases and metals buried within the lunar soil, which along with the water, could be extracted to make rocket fuel on the moon. The research appears in the October 22nd edition of the journal Science.

"If you took the 10 kilometer region around the LCROSS site, that is said to have 5 percent concentration of water, that would be equivalent to a billion gallons of water," said Tony Colaprete, the principal investigator on the Lunar Crater Observation and Sensing Satellite mission to search for water on the moon. A billion gallons is enough to fill 1500 Olympic-sized swimming pools. The lunar scientists now suspect that there is 50 percent more water than they had previously estimated.

Colaprete also said that given the large number of craters on the moon, which function as "cold traps" that accumulate molecules of water over billions of years, "potentially, you could have 10 to 100 times that total amount of water."

"We found some of the coldest places in the solar system and they’re on our moon. These places have temperatures that are so cold that they can preserve water ice in a vacuum for billions of years," said Michael Wargo, a chief lunar scientist at NASA headquarters in Washington, D.C.

The lunar water is thought to exist in "oases," or deposits, instead of being uniformly distributed across the moon. It also exists mainly in the form of water ice crystals.

"That's good news because water ice is very much a friendly resource to work with. It's easy to extract and turn it into a resource, you don’t have to warm it very much, you can pull it out of the dirt really easy," said Colaprete, who described a process of extraction whereby the ice-bearing lunar soil could be heated to 100 degrees Celsius to collect the water vapor.

During the live NASA teleconference, the scientists said that the amount of other materials they detected on the moon – including mercury, ammonia, methane, carbon dioxide, sodium and silver – may make up as much as 20 percent of the lunar dust plume kicked up by the impact of the LCROSS rocket.

Both discoveries could be instrumental in one day making it easier to set up a lunar colony, the researchers said, because of the high cost of transporting materials to the moon, which can exceed thousands of dollars per pound.

Last year, NASA shot a Centaur rocket carrying the LCROSS and Lunar Reconnaissance Orbiter from Cape Canaveral, Florida, and in October, they deliberately crashed the rocket at 6,000 mph into Cabeus, a cold, dark crater on the moon’s south pole that hasn’t seen sunlight in billions of years.

The impact sent up a plume of lunar soil and debris several miles over the crater’s rim, exposing it to sunlight. Meanwhile, the spacecraft collected data for four crucial minutes, allowing scientists to analyze the chemical makeup of the ejected lunar soil, before it too crashed into the crater. Since then, the LCROSS team has been sifting through the information to glean clues about earth’s 4.5 billion year-old neighbor.

So how did the water get there? According to Colaprete, it’s likely a combination of sources. One way it could have arrived is from solar wind depositing hydrogen into the lunar granules which contain oxygen atoms. Another way is from impacts by icy comets slamming into the moon, a theory supported by the observation of these other chemicals and hydrocarbons that also exist in comets.

The last manned lunar mission was Apollo 17 in 1972. In recent years, the U.S., along with Japan, China and India have launched various unmanned lunar mission. NASA is scheduled to launch two other lunar exploratory missions, GRAIL and LADEE in 2011 and 2012, respectively, to map the moon’s interior structure and further analyze the moon’s dust.

Sometime in the next several decades, a new generation of astronauts may return to set up a lunar outpost, setting the stage for future missions to Mars.

“In the next 20 years, next 10 years, you’re going to see the moon continue to expand in its diversity, and its complexity and its interest, among the communities of both laypeople and professionals and that’s going to pull us there,” said Colaprete.

Instruments currently orbiting the moon are allowing the scientists to map in much greater detail hydrogen-rich, lunar "permafrost" regions that may contain deposits of water ice and other compounds that could help support a future lunar colony.

But before that lunar colony can be set up, there has to be a more sophisticated understanding of where exactly the water is and how easy or difficult it will be to mine when it's found.

"The next step is to look at smaller and smaller scales at the lunar surface of the distribution of water as a resource," said Colaprete.

"If I were an astronaut walking along, how far do I have to walk before I find some water and how extensive are these pockets of water?"

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Topographic image of the Bay Area and continental shelf and slope. The coastline during the peak of the last ice age was at the shelf edge near the Farrallon Islands.

Before reading this post, make sure to check out QUEST’s video segment from last week about sea-level rise in the San Francisco Bay, which provides a nice overview of the problem low-lying areas in the greater Bay Area will face in the coming decades. As good as it is, the QUEST piece is really just an introduction to the problem of current sea-level rise. Sea-level rise is happening and more than 100 million people could be affected globally over the next century even under somewhat conservative projections. This is an tremendously complex problem that will require research across numerous scientific disciplines and creative problem-solving from engineers and urban planners. Like many of the posts I write for QUEST, I’d like to zoom out in terms of the timescales we are used to thinking about and share a little information about geologically recent sea-level changes in the Bay Area.

Over the past few million years, the Earth has flipped back and forth about 20 times between periods of significant continental glaciation, or ice ages, and briefer periods of much less ice. The peak of the most recent ice age was approximately 18,000 years ago. During this time, referred to as the Last Glacial Maximum by Earth scientists, the continental ice sheets that covered much of northern North America and northern Europe reached their largest extent in area. When such vast continental ice sheets grow they “borrow” water from the Earth’s water budget and, as a result, global sea level is lowered. Only 18,000 years ago sea level was 120 meters (400 ft) lower than it is at present.

The map above is a simple sketch map of the paleogeography of the Bay Area at this time*. Think about this for a moment — if you were standing at Land’s End Park on the northwest corner of San Francisco you would not be at the land’s end! The coast would be about 20 miles offshore of the current coast, just beyond the uplands that are now poking out as the Farallon Islands. What is now the Bay was a network of flat valleys with the ancestral Sacramento-San Joaquin River and tributary streams making their way through the narrow notch in the hills at Golden Gate. As temperatures warmed and the continental ice sheets began to melt sea level started to rise. That’s a simplified picture of what the landscape may have looked like at different stands of sea level, but what about the rate at which the sea rose?

The Pacific Institute, a nonprofit research institute based in Oakland, published a thoroughly researched and very readable report on sea-level rise and its impact on the California coast, which is also featured in the QUEST report. Estimates of future sea-level rise as stated in their report are between 1.0 and 1.4 meters (40-55 inches) by the year 2100. To be conservative (and to simplify a bit) let’s assume this present rate of sea-level rise is 1 meter per 100 years. If we now look at a reconstruction of sea-level changes since the Last Glacial Maximum we see the rise in sea level was not constant — depending on the rate of warming along with other factors the rate of rise varied. As you can see in the graph below the rate of rise slowed significantly about 8,000 years ago. From 18,000 years ago to 8,000 years ago sea-level rose approximately 100 meters (330 ft), which is an average rate of 1 meter per 100 years. In other words, the Earth will soon be experiencing a rate of sea-level rise it hasn’t experienced in several thousand years.

The most important uncertainties regarding our understanding of current and near-term sea-level rise are magnitude and rate — that is, how much and how fast. By studying the relatively recent past (geologically speaking) we can learn something about the effects varying rates of sea-level rise might have on the Bay Area. For example, how did bayshore ecosystems respond to rapid sea-level rise thousands of years ago? How will tidal marsh ecosystems respond to slow versus rapid sea-level change? The map below from the San Francisco Estuary Institute shows the different types low-lying bay shoreline that will be affected by future sea-level rise.

These environments, some of which are entirely human-made, will respond differently to sea-level rise. Further study of past environments and ecosystems and how they were affected by sea-level rise since the last ice age will play an important role in the broader goal to mitigate the consequences of a rising San Francisco Bay.

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UPDATE (9/2/2010):

Also check out this great video piece from QUEST a couple years ago to help you visualize what the Bay Area landscape was like 20,000 years ago and the kinds of animals that lived here. Definitely worth a look.

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* Check out this fantastic slide show from UC Berkeley Earth scientist Lynn Ingram here (link opens a PDF). This is  a great resource for learning more about the information scientists are collecting from the Bay’s sedimentary record to answer some of the questions I pose above.

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Artist's rendering of the LCROSS spacecraft and its upper stage Centaur rocket. Image courtesy of NASA.

Originally reported for KQED News.

Last year, NASA scientists in Mountain View made international headlines when they crashed a rocket into the moon and announced they had found water there.

On Tuesday, they revealed that the water – which exists as ice and vapor – isn’t spread out in vast oceans, but rather is concentrated in oases, and that the lunar surface appears to contain a wealth of other materials, from mercury to magnesium.

Both discoveries could be instrumental in one day making it easier to set up a lunar colony, the researchers said, because of the high cost of transporting materials to the moon, which can exceed thousands of dollars per pound.

“It’s water and much more,” said Anthony Colaprete, an astrophysicist at NASA Ames Research Center in Mountain View. “The others, from a scientific standpoint and a resource standpoint may prove to be as important or more important.”

Colaprete is the principal investigator on the mission to find water on the moon, which is known as LCROSS or the Lunar Crater Observation and Sensing Satellite. Last year, the scientists shot an unmanned spacecraft from Cape Canaveral, Florida, and in October, they deliberately crashed its rocket at 6,000 mph into Cabeus, a cold, dark crater on the moon’s south pole that hasn’t seen sunlight in billions of years.

The impact sent up a plume of lunar soil and debris several miles over the crater’s rim, exposing it to sunlight. Meanwhile, the spacecraft collected data for four crucial minutes, allowing scientists to analyze the chemical makeup of the ejected lunar soil, before it too crashed into the crater. In the nine months since then, the LCROSS team has been sifting through the information to glean clues about earth’s 4.5 billion year-old neighbor.

How wet is the moon?

“As wet as the Sahara, perhaps wetter in some places”, said Colaprete.

On Tuesday, at the third annual Lunar Science Forum at NASA Ames, researchers discussed everything from the physics of the LCROSS impact to the complex chemistry of the moon. Among their findings:

- The distribution of water on the moon is not uniform, but “chunky”, occurring in deposits in dark craters like the one LCROSS struck.
- The range of chemicals found on the moon is wider than once thought and includes mercury, magnesium, sulfur dioxide and possibly, formaldehyde, along with sodium, hydrogen sulfide, carbon dioxide and methane.
- The total amount of water in the target site and the plume observed by LCROSS: 26 gallons

So how did the water get there? According to Colaprete, it’s likely a combination of sources. One way it could have arrived is from solar wind depositing hydrogen into the lunar granules which contain oxygen atoms. Another way is from impacts by icy comets slamming into the moon, a theory supported by the observation of these other chemicals and hydrocarbons that also exist in comets.

The last manned lunar mission was Apollo 17 in 1972. In recent years, the U.S., along with Japan, China and India have launched various unmanned lunar mission. NASA is scheduled to launch two other lunar exploratory missions, GRAIL and LADEE in 2011 and 2012, respectively, to map the moon’s interior structure and further analyze the moon’s dust.

Sometime in the next several decades, a new generation of astronauts may return to set up a lunar outpost, setting the stage for future missions to Mars.

“In the next 20 years, next 10 years, you’re going to see the moon continue to expand in its diversity, and its complexity and its interest, among the communities of both laypeople and professionals and that’s going to pull us there,” said Colaprete. “There’s a lot you can do with the moon. It’s fundamental to understanding our place in the solar system and we’ve always appreciated that and recent studies have accentuated it.”

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