Tag Archives: Oceanography

Amusing Monday: Celebrating Alvin’s animals

This year is the 50th anniversary of Alvin, a deep-sea vehicle that has made some incredible scientific discoveries over the past half-century.

The latest issue of Oceanus magazine is a special edition that takes us through the history of Alvin, including its part in locating a lost hydrogen bomb, investigating the Deepwater Horizon oil spill and documenting the remains of the Titanic.

Read “The Once & Future Alvin,” Oceanus Summer 2014.

What really drew my attention to this issue is a photo feature called “Alvin’s Animals.” It was posted as a slide show in the online version of Oceanus. It registered high on my amusing meter, and I encourage you to click through the buttons that take you from one odd-looking creature to the next.

One of Alvin’s most significant discoveries came in 1977, when the submersible traveled to the Galapagos Rift, a deep-water area where volcanic activity had been detected. Scientists had speculated that steaming underwater vents were releasing chemicals into the ocean water. They got to see that, but what they discovered was much more: a collection of unique clams, worms and mussels thriving without sunlight.

These were lifeforms in which bacteria played a central role at the base of a food web that derives its energy from chemicals and not photosynthesis.

Since then, other deep-sea communities have been discovered and documented throughout the world, with hundreds of new species examined and named.

The Oceanus article also describes in some detail the just-completed renovation that has given Alvin new capabilities. The people responsible for various aspects of the make-over are interviewed in this special edition.

The first video on this page is by Woods Hole Oceanographic Institution celebrating Alvin’s 50th birthday. The second is a walk-around the newly renovated craft by Jim Motavalli, who usually writes about ecologically friendly automobiles.

Amusing Monday: Exploring the deep ocean — live

I’ve been captivated by live videos on the Internet this year, and I hope you won’t mind another live feed, this one from the sea floor of the Atlantic Ocean off the coast of Massachusetts.

The video comes to us live from a remotely controlled submarine traveling up to 10,000 feet below NOAA’s research vessel Okeanos Explorer. Be sure to click to full-screen. The current expedition will continue until Friday, but others are planned. If you don’t see anything, the activity may be over for the day. Hours normally are 5:30 a.m. to 1:30 p.m. in our time zone. See the mission’s web page, Northeast U.S. Canyons Expedition.

Reporter Seth Borenstein wrote about the expedition last week for The Associated Press.

Some of the most remarkable videos saved from the expedition can be found on the Photo and Video Log. While the live shots are surprising, the recorded ones truly are highlights of the exploration. A description of the work being done has been posted on the Daily Updates page.

Reports on earlier research by the Okeanos Explorer is organized by year and can be found on the Expeditions page.

A few answers regarding sea level rise

Because of the holidays, I did not get an immediate response from several climate experts I contacted following Nels Sultan’s comments about sea level rise in a blog post regarding “king tides.”

Earth at the winter solstice, Dec. 22, 2011 / NOAA photo

If you recall, Nels was making the point that the sea level in Seattle has been rising at a steady rate of .68 feet, or about 8 inches, per century since 1898, as reported by the National Oceanic and Atmospheric Administration.

His post included this statement:

“There is no real basis for the claims that sea levels will rise by 2.6 feet or 7 feet, or more. Globally, sea level rise has NOT accelerated. As found and reported by many researchers who specialize in this, including the eminent professor Bob Dean and other coastal experts.”

As a reporter, I’m not inclined to shoot back a response. I’d rather discuss the issue with experts in the field. That is what I did, and I think I have a better handle on the issue.

What I’m hearing is that the original estimates by the Intergovernmental Panel on Climate Change — a rise of between 7 inches and 2 feet by the end of the century — remain reasonable, but conservative given that they did not account for increased melting of the Greenland ice sheet. See this explanation by Stefan Rahmstorf soon after the release of the 2007 IPCC report. By the way, the range above accounts for the minimum and maximum across six climate-change scenarios.

Ever since, researchers have been trying to find ways to account for the melting of the Greenland ice sheet, but the uncertainties remain high. A widely cited paper by W.T. Pfeffer, J.T. Harper and S. O’Neel suggests that “most likely” starting point for further refinement is .8 meter, or 31 inches, of sea level rise by 2100.

In some ways, the authors of the Pfeffer paper were trying to limit some of the extremes being reported by others, so they concluded that sea level rise could not be more than 6 feet by 2100. Some folks have reported 6 feet as the top of the range, as unlikely as that extreme may be. Check out this explanation posed by Real Climate and this response by Pfeffer and his collaborators.

As for the Houston-Dean paper that Nels Sultan mentioned, those authors created “various problems” in their assumptions, according to Eric Steig, professor of Earth and Space Sciences at the University of Washington. One major problem was the starting date of 1930, as explained by Stefan Rahmstorf in Real Climate:

“Other start dates either before or after this minimum show positive acceleration. Picking 1930 for this analysis is thus a classic cherry-pick, and according to the authors that is no accident. They write in the paper: ‘Since the worldwide data of Church and White (2006)…appear to have a linear rise since around 1930, we analyzed the period 1930 to 2010.’ The interval was thus hand-picked to show a linear rise rather than acceleration.

“Houston & Dean use their result to question the future acceleration of sea level rise predicted by Vermeer & Rahmstorf (2009) for the 21st Century as a consequence of global warming. They argue that the 1930s acceleration minimum calls into question the semi-empirical link between global temperature and global sea level proposed by us in that paper. However, it is clear they never bothered to check this, because quite the opposite is the case: our semi-empirical formula predicts this acceleration minimum, as the graph above shows. As it turns out, this is an expected outcome of the mid-20th-Century plateau in global temperature.”

I also discussed this issue of sea level rise with Lara Whitely Binder, outreach specialist for the UW’s Climate Impacts Group. While sea level rise means one thing on the world scale, she told me, the local impacts can be quite different.

If you live in Neah Bay on the Olympic Peninsula, for example, you are not likely to see any sea level rise until at least 2080. That’s because the entire land mass is uplifting as a result of movement along the tectonic plates, and the uplift is predicted to be faster than sea level rise until late in the century.

On the other hand, Central and South Puget Sound may not be uplifting at all and could be sinking, which would intensify the effects of sea level rise. Areas built on fill, including portions of Olympia, also could be sinking as the fill settles, Lara said.

In addition to global rise in sea level and local tectonic shifts, factors affecting regional sea level rise include thermal expansion of ocean waters and changes in onshore and offshore wind patterns.

During El Niño events, sea level can rise as much as 12 inches for several months at a time. The Climate Impacts Group analyzed more than 30 scenarios from global climate models and concluded that the change in wind patterns as a result of climate change could decrease sea level by as much as 1 inch or possibly increase it by as much as 6 inches. Review the white paper “Sea Level Rise in the Coastal Waters of Washington State” (PDF 2.4 mb) for more details.

How much an individual property is affected by sea level rise depends on the slope of the beach. Given the same rate of rise, water will affect a house sooner when it is built on a gradually sloping beach as opposed to a steep slope. In any case, tides and weather will always play a major role in water levels.

Lara told me that a group of West Coast researchers is working on a new report about sea level for publication later this year by the National Academy of Sciences. I’ll try to review that paper when it comes out.

I wish to thank Eric Steig, Lara Whitely Binder, Cliff Mass, David Montgomery and Nate Mantua for responding to my inquiry.