Did you feel a small tremor rumbling underground last fall? Seismometers as far west as Seattle lit up on October 30. But the source of the recorded energy didn’t come from an earthquake. It came from Superstorm Sandy, an extreme hurricane that hit the East Coast thousands of miles away. What the…?

At the recent Seismological Society of America’s annual meeting, researchers presented their findings on seismic waves that are triggered by large storms and sometimes cause the ground at great distances to shake.

In the case of Sandy, the shaking was partly caused by the actual waves hitting the mid-Atlantic coastline. Of greater consequence were the waves colliding with other waves in the ocean, setting up a pattern of “standing waves” that reach the seafloor and transmit their energy. That force becomes seismic waves that travel through the crust and upper mantle under North America.

“They are not earthquakes; they are seismic waves,” says Keith Koper, director of the University of Utah Seismograph Stations. “Seismic waves can be created by a range of causes. We have beautiful seismic records of the meteor that hit Russia. That’s not an earthquake, but it created ground motion.”

Earthquakes, storms, and meteors are only three causes of seismic waves. Seismic activity can also occur from mining, traffic, construction, and even elephants communicating.

At the same meeting, researchers presented findings that Hurricane Irene may have caused aftershocks to a 5.8 magnitude earthquake in Virginia in 2011.

This isn’t the first time large storms have been linked to seismic waves, Koper adds. “Hurricane Katrina in 2005 was recorded by a seismic array in California, and they could track the path of the storm remotely using seismometers.”

Image: Keith Koper, University of Utah Seismograph Stations

Happy Earth Day! We would like to share a few recent headlines for you to peruse to ponder and protect our planet…

Pollution
From high to low, all around the world, pollution affects our world. Recent headlines show that “Toxic chemicals are accumulating in the ecosystems of the Himalayas and the Tibetan plateau,” according to Nature. Tiny plastic particles aren’t just trouble in the oceans; the Great Lakes contain millions of microplastics, too. The New York Times’ Dot Earth blog has a short post about the importance of not littering. And National Geographic has an article about how pollution on land can affect marine life like dolphins and local sea otters.

Colorado River
While many U.S. rivers have problems with pollution, the Colorado River’s mismanagement, overuse and drought put it atop the list of Endangered Rivers of 2013. National Geographic has an entire series on the Colorado River delta, and the New York Times has offered both an article and video last week on the region’s hopeful revival.

Drought
Speaking of drought… Do drought-stressed trees cry for help? French scientists are listening for clues. Climate change was not responsible for last summer’s Midwestern drought, according to NOAA, but then what was? And how might we be able to predict future droughts?

Climate Change
Climate change may not have caused of the recent drought, but it is responsible for other devastating events and looming disasters: bumpier flights, more storms, bark beetle plagues, drowned islands, failures in agriculture systems and more extinctions. Researchers are also getting a better handle on tracking climate change through mapping ocean eddies and looking at historic ocean temperatures and air pressure.

Ecology
How do species react to environmental changes? Rapid evolution, according to one study. Another study suggests that endangered species are already doomed. And Nature offers an update on a decades-long study of habitat fragmentation in the Amazon.

Energy
How has energy usage in our country changed over the past two hundred years? NPR has a graph (or four) for that. In response, Scientific American presents a diagram illustrating our potential for future alternative energy use and resources accompanying an article titled, “How to Power the World without Fossil Fuels.” Germany seems to have taken notice—the European country has ambitious renewable plans. But it’s not the only one. The U.S. had a huge year in 2012 for wind power. And, heading across the country soon? How about a solar-powered flight?

Earth Day
Finally, let’s truly celebrate the planet’s holiday with history, maps, jokes about Earth Day, and facts and photos of our beautiful home.

Image: Terra/ASTER/NASA and NASA Earth Observatory

Carbon dioxide is often the bad guy—warming the world and acidifying the ocean. But it’s not the only bad guy; there are other pollutants humans release into the air that damage our planet. And halting the release of those chemicals might be the key in beginning to stop the Arctic melt and to limit sea level rise.

As glaciers and ice sheets melt and warming oceans expand, sea levels rise by about 3 millimeters annually (just more than one-tenth of an inch). If temperatures continue to increase, sea levels are projected to rise between 18 and 59 centimeters (7 to 23 inches) this century.

Carbon dioxide can last in the atmosphere for hundreds of years, so it will take centuries to feel the positive effects of any actions we take now to limit CO₂—too late to protect many coastal communities on the front lines of sea level rise. However, other greenhouse emissions such as methane, tropospheric ozone, hydrofluorocarbons, and black carbon last for a far shorter time, anywhere from a week to a decade.

Previous research has shown that a sharp reduction in emissions of these shorter-lived pollutants beginning in 2015 could offset warming temperatures by up to 50 percent by 2050. Researchers at Scripps Institution for Oceanography, the National Center for Atmospheric Research (NCAR) and Climate Central decided to study how the same reductions in these pollutants might affect the rate of sea level rise. The team found that such cuts could dramatically slow rising sea levels—to an estimated 22 to 42 percent by 2100.

The research is published in Nature Climate Change.

“It is still not too late, by stabilizing carbon dioxide concentrations in the atmosphere and reducing emissions of shorter-lived pollutants, to lower the rate of warming and reduce sea level rise,” says co-author Veerabhadran Ramanathan of Scripps. “The large role of the shorter-lived pollutants is encouraging since technologies are available to drastically cut their emissions.”

Methane emissions can come from waste, agricultural practices and burning natural gas. Tropospheric ozone is often called the bad ozone and results from the interaction of sunlight with chemicals emitted by burning fossil fuels. Hydrofluorocarbons are emitted from refrigeration and air conditioning. And black carbon is basically soot—caused by diesel fuels and burning biomass like wood, a basic fuel source in many developing nations.

“It must be remembered that carbon dioxide is still the most important factor in sea level rise over the long term,” says NCAR’s Warren Washington, another co-author. “But we can make a real difference in the next several decades by reducing other emissions.”

Image: NASA

That’s what a recent paper in PLoS Biology asks—and doesn’t really answer.

Instead, it lays out a great argument, giving the pros and cons of using the controversial technique in addressing conservation issues. It also urges the two parties—synthetic biologists and conservation biologists—to get in the same room and talk about the possibilities and problems with open minds. In fact, the authors of paper organized a meeting this week in the United Kingdom, bringing the two groups of scientists together. (Ed Yong has an article about the meeting at National Geographic.)

The paper describes several examples of how synthetic biology could work to help conservation efforts—restoring habitats, supporting endangered species, and even reviving extinct species. It also lays out several examples of how synthetic biology could wreak havoc on the natural world. (The open-access article is very readable. We encourage you to review it or at least take a look at the examples in Table 1.)

The paper and meeting come on the heels of huge media coverage on de-extinction. National Geographic’s April issue on the topic garnered a lot of press and generated public interest. In some cases, these articles say, de-extinction could be just a few years away, if not closer.

The PLoS paper and de-extinction topic seemed to be a great opportunity to speak to Terry Gosliner, the Academy’s Dean of Science and Research, about the subject.

“Do you really want to encounter a saber-toothed cat in Muir Woods?” Terry joked when we sat down.

He sees huge potential risks in using synthetic biology for conservation, but admits that the meeting and discussion are a great idea. “Open dialogue is the only way to explore the topic, see the potential and understand what the concerns and dangers are,” he says. “Bad things happen when there isn’t discussion. Informed dialogue is the best way to deal with controversial issues.”

Terry believes some aspects of synthetic biology in the natural world could work, with appropriate regulation.

But he also sees that synthetic biology may not be the right approach. When thinking about threatened species, the problem is usually “habitat loss, not necessarily genetic constraints.” He uses the re-emergence of California condors as an example of this.

And in some cases, extinction is a natural process, Terry reminds us. Synthetic biology could just be more of humans interfering with nature, and not in a good way.

The resources going toward de-extinction could be better used to protect life before it goes extinct, Terry thinks. “If we use the same resources to address climate change and how we use energy,” Terry says, “We literally could save hundreds and thousands of species.”

And those energy and climate resources could be from synthetic biology. The PLoS paper cites a 2009 report on synthetic biology: “Many believe that synthetic biology will be one of the transformative technologies necessary to combat climate change, energy shortages, food security issues and water deficits.”

What do you think? Can synthetic biology save wildlife? Where do you stand on the issue?

How was western North America formed? Geologists have long held that as North America broke away from Pangea and headed west, it ran into the Farallon plate. Subducted under the North American plate, the The Farallon acted almost like a conveyer belt, creating the extensive area of elevated topography that dominates the West—the coastal ranges, the Rocky Mountains and the high plateaus in between. This mountainous area consists of dozens of crustal blocks of varying age and origin, welded onto the American continent over the past 200 million years.

But something was missing in this explanation, says Karin Sigloch, of Ludwig Maximilian University in Munich. “How these blocks arrived in North America has long been a puzzle.”

So with colleague Mitchell Mihalynuk of the British Columbia Geological Survey, Sigloch went to work on the puzzle. The scientists used a technique called seismic tomography. Seismic tomography makes it possible to probe the geophysical structure of Earth’s interior down to the depth of the lower mantle by analyzing the propagation velocities of seismic waves. The method can image the remnants of ancient tectonic plates at great depths, revealing ocean floor that subducted a long time ago, disappearing from the surface and sinking back into the mantle.

The new data from their study suggest that the Farallon Plate was far smaller than had been assumed, and underwent subduction well to the west of what was then the continental margin of North America. The researchers also determined that there was likely another, previously unrecognized oceanic plate involved in the formation of the West.

As the North American plate moved westward, the initially met and consumed the previously unknown oceanic plate, now detected seismologically beneath east coast of modern North America. Only then did the continent begin to encounter the Farallon plate. On its westward journey, the scientists conclude that North America overrode one intervening island arc after another—annexing ever more of them for the construction of its wild, wide mountains of the West.

The study is published in this week’s Nature.

Image: Karin Sigloch

I’m writing this from more than 8,000 feet (around 2,500 meters, for the more metric-ly inclined) above sea level, in the control room of one of the twin 6.5–meter Magellan telescopes at Las Campanas Observatory, near the southern end of Chile’s Atacama Desert. I’m tagging along on a night of observing with Jackie Faherty and Chris Tinney as they measure distances and chemical compositions of exotic objects known as brown dwarfs. For the next three Science Today entries, I’ll try my best to tell the story of this one night of observing and to give a sense of what Faherty and Tinney are attempting to learn about these tiny, faint stellar wannabes.

The night’s work starts in the afternoon. The instruments require calibration, which can take place long before the sky gets dark. Because the observations will involve taking both images (basically photographs) and spectra (a “fingerprint” of the light) of the brown dwarfs, they will use both the FourStar camera and the FIRE spectrograph. Astronomers have a more fastidious approach to their images than, say, your average Instagram user, so they carefully characterize the camera’s responsiveness and uniformity. For the spectrograph, they create a map of how the light splits into its constituent wavelengths using the equivalent of neon billboard lights aimed at the instrument.

At sunset, a few clouds in the southwest cause some concern: astronomers prefer their sunsets dull, unimpressive, and cloud-free. The worry passes, however, and as the sky darkens, the work begins in earnest.

Only four days from full, the moon brightens the sky considerably. For astronomers who observe in visible wavelengths (what we see with our eyes), this would ruin a perfectly good night. Consequently, many seek out “dark time,” defined as the first few nights before or after the new moon. Luckily, brown dwarfs show up best in infrared light, so tonight’s observations can take place in the “bright time,” three to five nights before or after the full moon. Indeed, the astronomers appreciate not having to deal with pitch-black observing conditions: “It’s inconvenient. You can’t see the clouds, and you trip over things,” Tinney notes.

A little more calibration occurs as the sky darkens, including pointing and focusing the telescope, and then the observations begin. “The focus at the beginning of the night changes rapidly because the temperature is dropping,” Faherty explains. “So we take shorter exposures, and continually monitor the images for out-of focus stars, which look like little donuts.”

Ultimately, Faherty and Tinney want to determine each object’s precise location in the sky—a process known as astrometry—as well as its light fingerprint—a process known as spectroscopy.

Particularly for this kind of project, astronomers need excellent “seeing,” which refers to “the blurring the atmosphere produces,” as Tinney describes succinctly. More blurring means the light gets spread out over a larger area of the detector, making precision work on faint brown dwarfs far more challenging.

Astronomers describe the quality of seeing in terms of the apparent angular diameter of a star. Optimal observing conditions at Las Campanas can yield seeing of 0.4 arcseconds or better—equivalent to the diameter of a penny observed from a distance of twelve miles (nearly twenty kilometers). This evening started with seeing around 0.5 arcseconds, but as the night wears on, the seeing drops to nearly 0.3 arcseconds! A great night! (Or perhaps simply observational karma: on Faherty’s last visit to the Magellan telescope, the seeing averaged 1.4 arcseconds, and the observatory shut down because of high winds. C’est l’astronomie.)

Amazingly, these high-quality observations can translate into even more impressive precision when it comes to locating the brown dwarfs relative to the other stars in the image. The resolution of the detector (about 0.16 arcseconds per pixel for FourStar) combined with good seeing means they can pinpoint an object’s location down to a few milliarcseconds—that’s right, 4% the apparent size of the object itself! Such excellent conditions also make it possible to tease apart the atmospheric properties of some of the faintest compact sources in the vicinity of the Sun.

Tomorrow, I’ll share a little more about brown dwarfs and the particular challenge that Faherty and Tinney plan to address, and on Wednesday, I’ll give a summary of how the evening’s work went and what it could mean for the next steps in brown dwarf science.

Ryan Wyatt is the director of the Morrison Planetarium and Science Visualization at the California Academy of Sciences.

Image:  Karl Schultz

When you and I look at spiders, we might see something creepy or cool (depending on your inclination), but when these scientists look at spiders, they see millions of years in the past.

Charles Griswold, Hannah Wood, Rosemary Gillespie and Nick Matzke painstakingly studied a superfamily of spiders called Palpimanoidea, aka assassin spiders.

The Academy and University of California researchers wanted to determine how these spiders are related and distributed and how that’s changed for the millions of years they have lived on Earth.

This superfamily has been assembled and separated many times over the past three decades.  The superfamily includes the trap jaw spiders (Mecysmaucheniidae), forest rubies (Stenochilidae), the mysterious Hutton’s spider (Huttoniidae), palp-footed spiders (Palpimanidae) and the pelican spiders (Archaeidae).

They’re called assassin spiders because all of the families except the trap jaw spiders hunt, kill and eat other spiders. Trap jaw spiders have an unusual feeding pattern, too. They have incredibly strong and fast jaws that lock open and then release quickly to trap prey.

While most of the living species within the assassin spiders live in the southern hemisphere, grouping these spiders is tricky because they have disjunct distributions, separated by barriers, namely large oceans.

Scientists love when things are tricky: it raises new questions to research. That couldn’t be more true for this group of folks. Charles has always been interested in biogeography and continental drift. Rosie Gillespie has always been interested in life on islands—what lives there, how did it get there and how did it diversify? Hannah’s fascinated by the pelican spiders and Nick is a paleontologist and computational biologist, attracted by the statistics of dating phylogenies.

It’s good that their interests are diverse, Charles says. “Science has become technologically and mathematically complex. It now requires a team of researchers.”

Hannah and Charles traveled throughout the southern hemisphere collecting and studying these spiders for many years. To answer the tricky questions this superfamily poses, they began with a thorough comparative morphology of all the spiders, living and extinct. Many of the fossils were specimens trapped in amber—which preserves the spiders “like new,” Charles says.

The scientists used whatever tools they could get their hands on—microscopy, current dissection technology, CT-scans, even the synchrotron at the Advanced Light Source at UC Berkeley.

The team gleaned data from DNA collected for every living spider. Then came the number crunching. Data were processed on the computer cluster here at the Academy and the San Diego Super Computer Center.

Charles explains that their findings confirm four different theories.

First, they confirm that these spiders all belong to Palpimanoidea.  “The phylogeny and classification encompasses the true scope of the superfamily,” Charles says.

Second, one of the fossil spiders they studied, an Archaeidae species, was discovered in the northern hemisphere. But all of the living relatives reside in the southern hemisphere. As David Byrne might ask, “How did I get here?” Charles and Hannah have an answer—continental drift. The lineage is so ancient, it’s consistent with the dates of continental drift.

Third and fourth, these spiders are found on the islands of Madagascar and New Zealand.  Geologists know that these two islands were originally pieces of their nearby continents that became separated. When they broke-off is clear, Charles says, but what is controversial is if some life forms have been around since the islands were connected to continent. .  Many animals and plants may have dispersed there.  The dates of these spiders originate prior to island separation, showing they have endured since the islands first broke away from the continents.

This superfamily of spiders, Charles says, is one of the “best examples of distribution that reflects continental drift. The distribution patterns, age of the fossils, and dates of phylogenic diversification are old enough. It’s one of the best documented cases of the results of continental drift.”

If you’ve seen our Earthquake exhibit, you know there are other examples of animal and plant evidence of continental drift. These spiders add nicely to it.

The study was published last month in Systematic Biology.

Charles will now take these methods to look at the biogeography of other groups of spiders. Hannah is looking more deeply into the trap jaw mechanism of those amazing spiders. Stay tuned for more spiderific stories!

Huttonia spider image: SE Thorpe/Wikipedia

Four amazing and passionate scientists discussed different aspects of our changing world—wildlife, drought, storms and the tree-ring record—at a press conference titled, “Did Climate Change Cause Superstorm Sandy?”

Remember, these are scientists, not politicians (see more in Andy Revkin’s New York Times blog). They need evidence to see causal effect between one event and another. And for these recent storms and weather patterns, there just isn’t enough evidence. Yet.

But are these researchers glad that these events are focusing Americans’ attention (including the President in his recent State of the Union address) on climate change? Most definitely. Yes.

Here’s what they do know. Climate change is affecting the probability of storms like Sandy and Nemo. There is evidence that in our warming world, severe storms will happen more frequently.

Researchers understand that global warming and other human-related activities are affecting where animals live, move and mate, and when plants bloom.

Scientists also know that temperature increase is one factor in drought. Texas temperatures have risen steeply in just the past 15 years and drought has increased.  And now Texans are talking about climate change, said John Nielsen-Gammon of Texas A&M University. The drought alone didn’t alarm them about climate change, but the decreased water supply has made people and politicians alike take notice.

And the speakers are hopeful and passionate that we’ll start doing something about these effects—reducing fuel emissions, restoring habitats, becoming more aware of climate change.

What do you know and feel? Share with us here.

Midwest drought image: cwwycoff1/Wikipedia

There were no fatalities, however several hundred people were injured, mostly from flying glass. Over a hundred remain at the hospital.

Scientists believe there is no correlation to today’s flyby of Asteroid 2012 DA14.

From NASA’s website:

According to NASA scientists, the trajectory of the Russian meteorite was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. Information is still being collected about the Russian meteorite and analysis is preliminary at this point. In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14′s trajectory is in the opposite direction, from south to north.

Nature has a great video on its site and explains why no one saw this coming:

Although a network of telescopes watches for asteroids that might strike Earth, it is geared towards spotting larger objects — between 100 metres and a kilometre in size.

Scientific American is reporting that this object was likely only “15 meters… when it hit the atmosphere.”

Want to see how one blogger mapped the trajectory of the meteor? Check it out here.