Stories tagged Earth Structure and Processes

Nov
16
2011

If you look at the U.S. Nuclear Regulatory Commission’s interactive map of nuclear power plants in the United States, you will see several in states bordering the Atlantic Ocean. This prompted the Nuclear Regulatory Commission to request the U.S. Geological Survey (USGS), along with other governmental and academic partners, to research the potential for tsunamis to strike the U.S. Atlantic and Gulf of Mexico coasts, and prepare maps using sonar (originally an acronym for SOund Navigation And Ranging). Note that the March 11, 2011 earthquake near Honshu, Japan, created a tsunami that resulted in a nuclear disaster that is still being remediated.

NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.
NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.Courtesy National Oceanic and Atmospheric Administration
Through this research, initiated about five years ago, the leading potential source of dangerous tsunamis to the East Coast was identified as landslides, either originating in submarine canyons or on the continental slope of the submerged margin of the continent of North America.

According to USGS marine geologist Jason Chaytor, many years of data collection and integration of existing data sets was needed in order to produce seafloor maps with the resolution needed to identify all of the relevant features for this study. The first field effort of this project was a multibeam bathymetric mapping cruise conducted aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Nancy Foster from June 4 to June 16, 2011. Using echosounders installed on the hull of Nancy Foster, the science team mapped canyons and shelf regions at high resolution over more than 380 square miles (1,000 square kilometers) of seafloor from south of Cape Hatteras, located offshore of North Carolina, to the eastern tip of Long Island in New York.
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).Courtesy United States Geological Survey


A number of submarine landslides, some previously unknown, were either partly or completely mapped. Characteristics collected include the size and number of landslides, soil and rock properties, the water depth they occur in, and the style in which they fail. This information is often used in numerical modeling of tsunamis generated by landslides.

The scientists detailed their findings in the September/October issue of the USGS newsletter Sound Waves.

Nov
11
2011

On November 10, 2011, at 17:25 UTC (or 11:25am Central Standard Time), a shallow quake occured in Greece about 11.8 miles NE of the town of Patras. According to the European-Mediterranean Seismological Centre, this earthquake had a magnitude of 5.1 (later downgraded to a 4.6) and was a relatively shallow quake at 5 km (approximately 3.1 miles) below the Earth's surface.

This region is characterized by a high level of seismicity, and small tremors are continually recorded along the coast of Patras. Another interesting aspect of Patras is that in antiquity, there was an ancient oracle, over a sacred spring, dedicated to the goddess Demeter. Professor Iain Stewart from the University of Plymouth has been studying a supposed link between ancient. sacred places in Greece and Turkey and seismic fault lines. Many ancient temples and cities lie along those fault lines and this may not be merely due to chance, but they may have been placed there deliberately.The Temple of Apollo at Delphi with Mount Parnassus in the Background
The Temple of Apollo at Delphi with Mount Parnassus in the BackgroundCourtesy Wikimedia Commons

For example, the Oracle at Delphi has been given a geological explanation. The Delphi Fault (running east-west) and the Kerna Fault (running SE-NW) intersect near the oracular chamber in the Temple of Apollo. In that area, bituminous limestone (i.e. limestone containing bitumen, a tarlike deriviative of petroleum) has a petrochemical content as high as 20%. Analysis of spring water in the area showed the presence of hydrocarbon gases, such as ethylene. Geologists have hypothesized that friction from fault movement heats the limestone, causing the petrochemicals within to vaporize. It has been suggested that exposure to low levels of the sweet-smelling gas ethylene would induce a trance, or euphoric state. Could the naturally occuring ethylene account for the strange, prophetic behavior of the Pythia (the priestess at the Temple of Apollo)?

The Delphi research is certainly persuasive, and received favorable coverage in the popular press and Scientific American, but it has come under criticism. Critics argue that the concentrations of ethylene identified by the researchers would not be sufficient to induce a trance-like state, and thus the connection to the mantic behavior of the Pythia is dubious.

Report: Geomythology: Geological Origins of Myths and Legends
Article: Breaking the Vapour Barrier: What Made the Delphic Oracle Work?
Report: Oracle at Delphi May Have Been Inhaling Ethylene Gas Fumes

Related Report: Earthquake Faulting at Ancient Cnidus, SW Turkey

Oct
28
2011

What do a banana and a chunk of coal have in common? Carbon!

Dr. Peter Griffith, Director of NASA's Carbon Cycle and Ecosystems office, spoke to twenty of us training to be Earth Ambassadors for NASA about why it's important to teach people about the way carbon moves around on our planet, in order to help them understand climate change.

He showed us this fantastic video that describes the Carbon Cycle on earth and describes how "young, fast carbon" like that in a banana differs from "old, slow" carbon, like that in coal and other fossil fuels.

See video

Dr. Griffith also described how you can tell the difference between objects containing old carbon and young carbon by looking at the radioactive decay of carbon 14. Carbon in its normal state is called carbon 12, or C12. However, cosmic rays, like those from the sun, convert some atmospheric carbon into a slightly radioactive form called carbon 14, or C14. Over time, this carbon decays back into Carbon 12.

All living plants and animals contain some C14, since they constantly take in atmospheric carbon dioxide.

Fossil fuels like coal and oil, which have been underground for millions of years, contain only C12 (fully decayed Carbon,) while a banana still contains some C14 from atmospheric carbon dioxide the banana tree absorbed.

It is not surprising that the carbon downwind of power plants burning coal is mostly C12. Trees can also lock up carbon in their trunks and branches in for many years.

The carbon released by burning fossil fuels and setting tropical forests ablaze is carbon that would naturally have remained "locked" up. Human activities like these are creating an excess of long-lived carbon dioxide gas in the atmosphere and are causing our world's climate to warm.

NASA and other scientists are working hard to study the science of climate change. How our planet and its inhabitants will respond to the challenges resulting from this change remains to be seen.

Oct
27
2011

Servicio Nacional de Geología y Minería (SERNAGEOMIN) raised the alert status for the Cerro Hudson volcano in southern Chile recently. The Chilean government reported that before this morning nearly 900 volcanic earthquakes were noticed, most of which were not felt by residents living in the area. 119 people are currently evacuated from the Lake Caro area, and authorities are trying to evacuate another 13 individuals.

There are now three steam vents on the volcano, one of which is also emitting ash. Some photos taken from a recent flyby of the volcano can be seen here.

The ice-filled caldera (10-km-wide, or ~ 6.2 miles) of the Cerro Hudson volcano was not recognized until its first 20th-century eruption in 1971. Cerro Hudson is the southernmost volcano in the Chilean Andes related to subduction of the Nazca plate beneath the South American plate, and is 280 km (~ 174 miles) east of the Nazca-Antarctic-South American triple junction. An eruption about 6700 years ago was one of the largest known in the southern Andes during the Holocene, and a 1991 eruption was Chile’s second largest of the 20th century.

News report: Hudson Volcano forces evacuations in Southern Chile
Eruptions blogpost: Alert Status Raised to Red at Chile’s Hudson

See video

Oct
06
2011

[SETTING: Ted and Lily are in line at the cafeteria.]

Ted: [Leans over a little, like he’s sharing a secret.] I just heard from SAHRA that the National Science Foundation is funding another Critical Zone Observatory at the University of Arizona. That’ll make six CZOs.

Lily: [Shocked.] Sounds serious!

Ted: Well, yeah. I mean, the critical zone is basically the area along the Earth’s surface between the treetops aboveground and the groundwater table belowground. That’s where we do our day-to-day living and a lot of really important life-sustaining natural processes happen, like water and nutrient cycling.
Variety is the spice of life
Variety is the spice of lifeCourtesy cafemama

Lily: I was talking about Sarah. Who’s she?

Ted: [The miscommunication dawns on him.] Not Sarah, SAHRA. The Sustainability of semi-Arid Hydrology and Riparian Areas. They’re a Science and Technology Center based at the University of Arizona.

Lily: [Relieved.] Oh. Gotcha. Back to the Important Area Thingamabob. It sounds like a really big area with a whole lot going on. How’s anyone going to observe it?

Ted: You’re right. The critical zone is a massive area and studying it is daunting, but the NSF’s got something going on with these CZOs.

Lily: [Slightly annoyed.] Please chew with your mouth closed. You’re getting alphabet soup all over my shirt.

Ted: [Indignant.] What? Just ‘cause you can’t swim in my alphabet soup…

[Lily glares at Ted.]

Ted: [Sheepish.] Anyway, I was saying about how the Observatories are intended to be a resource for international collaborations between science disciplines. You know, interdisciplinary, multi-disciplinary, and such. This will allow scientists from geology, ecology, hydrology, etc to work together so we can understand how all the components interact in the Critical Zone.

Lily: Ah-ha! So the Observatories are like a potluck. Everyone brings their specialty to the table to make a whole meal.

Ted: Sure. And the best potlucks happen when lots of people bring something to share and there’s a variety of deliciousness.

Know what else? Each of the six Observatories is located in a different climate. More variety! By comparing the same processes in different climates, scientists will be better able to figure out how the critical zone will change under climate change.
Lily and Ted: On the set
Lily and Ted: On the setCourtesy pchow98

Lily: Huh. I had no idea that science news could make me so hungry.

Ted: Did you even hear what I just said?

Lily: [Mumbles to herself.] Where do you suppose I can get a recipe for tater tot hot dish? [To Ted.] Wait… whatdidjasay?

Ted: [Sighs.] Nevermind. I’m going to get some chocolate pudding. Want some?

Oct
05
2011

You are Cordially Invited

Publication Party, Public Reading, and Book Signing Event

for
FOOL ME TWICE: Fighting the Assault on Science in America
by
SHAWN LAWRENCE OTTO

Introduction by Don Shelby
Emcee Jim Lenfestey

"A gripping analysis of America's anti-science crisis."
Starred Kirkus Review
“In this incredible book, Otto explores the devaluation of science in America.”
Starred Publishers Weekly Review

You know you want to read it. Click here for more info
You know you want to read it. Click here for more infoCourtesy Shawn Lawerence Otto

Tuesday October 18, 2011 at 7PM
Target Performance Hall, Open Book
1011 Washington Avenue South, Minneapolis
(click here for directions and free parking)
This event is free and open to the public

sponsored by
the Loft Literary Center
the Science Museum of Minnesota

no reservation required, but click here to RSVP to help us plan

Beer, wine and light refreshments served
Books for sale at the event
Free book by drawing. To qualify: A) post about the event on Facebook B) tweet at the event with hashtag #FoolMeTwice and mention @ShawnOtto

Sep
20
2011

There’s been some buzz about the relationship between clouds and climate recently, prompting Andrew Revkin of the New York Times’ Dot Earth blog to get his panties in a twist about the “…over-interpretation of a couple of [scientific] papers…”

What gives? I wanted to know too, so I’ve done a bit – ok, a lot – of research and this is what I can tell you: The heart of the discussion is not whether there is a cloud-climate connection (that’s clear), but rather over what that relationship behaves like. There are at least three possible theories, but before we get to those, let’s review some important background concepts.

Gimme the Basics First

Cloud Formation

First, scientists think of air as units of volume called air masses. Each air mass is identified by its temperature and moisture content. Clouds are basically wet air masses that form when rising air masses expand and cool, causing the moisture in the air to condense. You can see the process in action yourself just by exhaling outside on a cool morning. The Center for Multiscale Modeling of Atmospheric Processes has a webpage to answer your other questions about clouds.

Earth’s Energy Budget
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow).  Outgoing energy is radiated (red).  The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow). Outgoing energy is radiated (red). The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.Courtesy NASA

Energy from the Sun is essential for life on Earth. Let’s pretend the Earth has an “energy budget” where solar energy is like money, absorption is like a deposit, reflection is like a transfer, and radiation is like a withdrawal. It’s not a perfect analogy, but it’ll work for starters: Most of the incoming solar energy (money) is absorbed by (deposited into) the ocean and earth surface, but some is absorbed or reflected (transferred) by the atmosphere and clouds. Most of the outgoing energy is radiated (withdrawn) to space from the atmosphere and clouds. The figure to the right illustrates this process.

The Greenhouse Effect

Thanks to the greenhouse effect, our planet is warm enough to live on. The greenhouse effect occurs within the earth’s energy budget when some of the heat radiating (withdrawing… remember our budget analogy from above?) from the ocean and earth surface is reflected (transferred) back to Earth by greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapor. This National Geographic interactive website entertains the concept.

Climate Change

Climate change is occurring largely because humans are adding more greenhouse gases to the atmosphere. More greenhouse gases in the atmosphere means more heat reflected back to earth and warmer temperatures. Warmer temperatures might sound pretty good to your right now (especially if you live in Minnesota and could see your breath this morning as you walked to school or work), but it’s not. Why? Check out NASA’s really great website on the effects of climate change.

Alright, already. What’s the climate-cloud relationship?

From what I can tell, there are three possible theories about the climate-cloud relationship:

  • Clouds actively drive climate change. This is a linear process where clouds reflect too much heat back to Earth, which increases the average global temperature and causes climate change.
  • Clouds passively blunt climate change. This is a cyclical process where more climate change includes increasing average global temperature, which increases average global evaporation, which creates more clouds. More clouds absorb more heat, keeping the average global temperature from rising even faster and lessening climate change. This slows down (note: it does not stop) the rate of climate change.
  • Clouds passively amplify climate change. This is a cyclical process where more climate change includes increasing the average global temperature, which increases average global evaporation, which creates more clouds. More clouds reflect more heat back to Earth, which raises the average global temperatures and worsens climate change. This speeds up the rate of climate change.
  • So which is it? Probably NOT Theory #1. Maybe Theory #2… or maybe it’s Theory #3? Scientists aren’t quite sure yet, so neither am I, but the evidence is stacking against Theory #1 leaving two possible options. The next big question seems to be surrounding the size of the effects of Theory #2 and Theory #3.

    Using what you just read about cloud formation, the earth’s energy budget, greenhouse gases, and climate change (Woah. You just learned a lot!), what do you think? What’s the climate-cloud relationship?

    If you want, you can read more about what scientists are saying about the climate-cloud relationship here:

May
12
2011

Mississippi River Levee in Baton Rouge, LA, taken May 11th 2011.: Panorama of the Mississippi River levee in Baton Rouge, LA near Louisiana State University, taken May 11th 2011.
Mississippi River Levee in Baton Rouge, LA, taken May 11th 2011.: Panorama of the Mississippi River levee in Baton Rouge, LA near Louisiana State University, taken May 11th 2011.Courtesy Azure Bevington
You might have heard about the terrible flooding that is occurring all along the Mighty Mississippi. As I write this I am sitting in Baton Rouge, Louisiana hoping the levees will hold. Normally the river in Baton Rouge is far below the tops of the levees. Flood stage, which is the water level at which the river would begin to flood surrounding areas without the levees acting as barriers, is 35 ft. Right now the water level is 42.8 ft and has risen 8 ft in just the last week. It is projected to crest at 47.5 ft and remain at that level for 8 to 10 days; this is higher than the previous record set in May 1927 of 47.28 ft. The tops of the levees that protect Baton Rouge are between 47 and 50 ft, they are currently sandbagging in areas less than 48 ft. Besides the possibility of overtopping there are also other problems that we need to look out for. When the river level remains high for an extended period of time the water can seep in and begin to saturate the soil, this can possibly weaken the levee structure. There is also the possibility of water going under the levee; this can result in sand boils, where the water bubbles up through the soil. It is very unlikely that this will happen, as the levees are strong and well constructed, but we need to be on the lookout for any problems.

Here in Baton Rouge we are much better off than many who live in communities within the Atchafalaya Basin, where the expected opening of the Morganza spillway could cause flooding of over 3 million acres (Click here to see a map of projected flooding in the basin) Many of these folks have already begun to sandbag their homes and to prepare to leave the area. The Morganza spillway is a large controlled gated structure that will divert water from the Mississippi River into the Atchafalaya Basin. The Atchafalaya Basin is a low lying cypress swamp that normally receives 30% of the flow of the Mississippi River through the Old River Control structure through the Atchafalaya River that winds its way through the swamp. This flood is projected to be larger than the 1973 flood and possibly even larger than the 1927 flood that devastated communities along the river, and brought about the passage of Flood Control Act of 1928. The magnitude of this year’s flood has already resulted in the opening of the Bonnet Carré spillway which diverts water into Lake Pontchartrain, this reduces the water levels as the River flows past New Orleans.

Stay tuned for updates on the flooding in Louisiana.

Have any of you been affected by the flood waters?

May
02
2011

the ocean's 5 major gyres
the ocean's 5 major gyresCourtesy NOAA
We often talk about the ocean ecosystem. And, indeed, there is really just one, world-wide ocean, since all oceans are connected. An Indian Ocean earthquake sends tsunami waves to distant coasts. Whitecaps look as white anywhere in the world. The ocean swirls in similar patterns.

However, oceanographers do find differences from place to place. For example, let’s take a closer look at the chemistry of two swirls, or gyres as they’re more properly called. Scientists have found a micro difference between the North Atlantic Gyre and the North Pacific Gyre. The Atlantic generally has really low levels of phosphorus, measurably lower than the North Pacific Gyre.

the element phosphorus among its neighbors in the Periodic Table of the Elements
the element phosphorus among its neighbors in the Periodic Table of the ElementsCourtesy modified from Wikipedia
Phosphorus is a very important element in living things. For example, it’s a necessary ingredient in ATP (adenosine tri-phosphate), the energy molecule used by all forms of life. Phosphorus is picked up from seawater by bacteria. All other marine life depends upon these bacteria, either directly or indirectly, for P. Therefore, if you’re bacteria living in the impoverished North Atlantic Gyre, you’d better be really good at getting phosphorus.

And they are!

Oceanographers at the Center for Microbial Oceanography: Research and Education (C-MORE) at the University of Hawai`i have made an important discovery. C-MORE scientists Sallie Chisholm, based at the Massachusetts Institute of Technology and her former graduate student Maureen Coleman, now a scientist at the California Institute of Technology, have been studying two species of oceanic bacteria. Prochlorococcus is an autotrophic bacterium that photosynthesizes its own food; Pelagibacter, is a heterotrophic bacterium that consumes food molecules made by others.

Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.
Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.Courtesy C-MORE
Drs. Chisholm and Coleman took samples of these two kinds of bacteria from both the Atlantic and Pacific Ocean. The Atlantic samples were collected by the Bermuda Atlantic Time-Series (BATS) program. The Pacific samples were collected in the North Pacific Gyre (about 90 miles north of Honolulu) by the Hawai`i Ocean Time-Series (HOT) program. The scientists discovered surprising differences in the genetic code of the bacteria between the two locations:

  • First of all, the Atlantic populations of both bacterial species have more phosphorus-related genes compared to their Pacific cousins. (Picture Atlantic microbes in Superman outfits with a big "P" on their chests!)
  • Secondly, in the Atlantic, Prochlorococcus has different kinds of P-related genes compared to Pelagibacter. Perhaps this means the two microbial species have evolved over time to use different phosphorus sources, to avoid competing with one another for this limited resource.

Drs. Chisholm and Coleman have discovered important micro differences between bacteria of the same species in two oceanic gyres. Now we can better understand how these microbes are working to recycle an important nutrient beneath the whitecaps.

Reference: October 11, 2010 issue of the Proceedings of the National Academy of Sciences

Mar
17
2011

Aren’t budgets all about money? Don’t they track how many $$$ come in and how many $$$ go out?

That’s right; so what’s a carbon budget? A carbon budget tracks how much carbon, C, goes in and out of a natural area.

Right now, we’re worried about too much C going into our planet’s atmosphere. This excess C is causing global warming, sea level rise, ocean acidification and other environmental problems. These are BIG problems! We can begin to fix these problems if we do a carbon budget and really know how much carbon is where.

Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?
Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?Courtesy Sergio Signorini, North American Carbon Program
Along with others, scientists at the Center for Microbial Oceanography: Research & Education (C-MORE), based at the University of Hawai`i, have begun to track C in the ocean off the eastern United States. The study area includes a LOT of water! -- all the seawater from high tide out to 500 meters deep, shown by the black line in the map, in the Gulf of Maine (GoM), the Mid-Atlantic Bight (MAB), and the South Atlantic Bight (SAB.)

Imagine your money budget. Let’s say we track your $$$ in and out of 4 categories. Money comes into your pocket from 2 categories, mowing the neighbor’s lawn and babysitting. Money goes out when you pay for movies and snacks.

In the same way, scientists want to track C as it moves between the coastal water “pocket” and 4 nearby areas: the coastal land, the atmosphere above, seafloor below, and the deeper ocean offshore. Where is C leaving the coastal water? Where is it entering?

But wait! Coastal zones are only small slivers of water, compared to the open ocean around the world. Why bother to track carbon in coastal waters?

Ah ha! Coastal waters are very important in C budgeting. Notice the red color in the map above. Red means there's a lot of chlorophyll. Chlorophyll is the green pigment important in photosynthesis, the process that plants use to take in C and fix it as sugar. The red in the map shows that coastal waters are richer in carbon than the open ocean.

Understanding the C budget of coastal waters is one small but important step in solving global warming and other environmental problems.

Reference: Ocean Carbon & Biogeochemistry Winter 2010 OCB Newsletter; Vol. 3, No. 1.