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Monday
Mar222010

What do expectant parents and the Chilean earthquake have in common?

The recent Chilean earthquake was a disaster on a mind-boggling scale; one that had its genesis beneath the sea.  The temblor, and all those in Chile before it, including the biggest ever recorded anywhere, resulted from the Nazca plate sliding down under the South American plate, under the sea to the South West of Santiago.  Well, it doesn't exactly slide, I always imagined it would sound like a creaking door if you could speed up the process a few zillion times.  The upward pressure this collision puts on the South American plate is immense and produces the longest mountain range in the world, the Andes.

Anyway, this most recent slip, which shifted about 10 meters and registered 8.8 on the Richter scale, caused a small tsunami.  Now some researchers from Scripps and UCSD want to know whether it was because of the sea floor movement itself, or because the quake triggered undersea landslides ("slumping") that produced the wave.  They are going to do some nifty multi-beam sonar work to map the seafloor changes in unprecedented details.  Sonar technology has become a really cool tool these days; the same sorts of benefits that new parents reap when they ultrasound their new bundle of joy also give scientists a fantastic new view on the sea floor.  Just check out this example of a shipwreck revealed by NOAA's nautical survey side-scan sonar.

Sunday
Mar212010

Bon Voyage, Plastiki

Some enterprising folks have built a tri-maran out of 12,000 two liter plastic softdrink bottles.  Dubbed the "Plastiki", she took to sea today, on her maiden voyage from San Francisco to Sydney.  Along the way, the Plastiki will serve as a floating demonstration platform for sustainable technologies, and will spend some quality time in the Great Pacific Garbage Patch, where vast amounts of floating plastic debris are becalmed in the heart of the enormous gyre current of the North Pacific.

Follow the Plastiki on Flickr here, and on their website here.  Best of luck and kind winds, folks.  If you begin to lose buoyancy, I guess you can always reach overboard and grab another bottle from among the flotsam, you know, to repair the hull with.  :-/

Friday
Mar192010

Ului inches closer

Looks like Ului will cross the coast right over the Whitsunday Islands.  Good luck to the folks in Proserpine and Bowen.

This picture from the Australian Bureau of Meteorology

Friday
Mar192010

Cyclone Ului approaching the Queensland coast

Cross your fingers for the people of Queensland, Australia, who are facing an impending cyclone, Ului.  It was just downgraded to a Category 2, but you never relax with these things right?  Tourists and researchers have been evacuated from Heron Island and several others, but it looks like it might cross a little further north.  Here's hoping it avoids major populated areas.

Friday
Mar192010

Whale sharks arrive early at Ningaloo Reef, Australia

I have never been to Ningaloo (great name, right?) - its WAY on the other side of Australia from where I grew up - but its a fascinating place.  Whale sharks gather there every year, and this year it looks like they turned up earlier than usual.  Whale shark aggregations are amazing events and the one at Ningaloo is one of the biggest.  Why gather? Why Ningaloo?  Why then?  How do they know where to go?  These are just some of the great mysteries of whale shark gatherings; its amazing that we know so little about the worlds largest fish.

Friday
Mar192010

If you can catch lightning in a jar, why not gas in a puddle?

Imagine if you could take all the greenhouse gases and somehow keep them away from the atmosphere, where they would otherwise contribute to global climate change.  Well that's kind of the idea behind SOFEX, a huge experiment done by marine scientists a few years back (my buddy and fellow Aussie Pete Strutton was involved).  The idea stemmed from an observation that the growth of plankton (which absorb carbon dioxide as they grow and multiply) in the oceans is limited by some nutrients, especially iron.  So, if we fertilise the oceans with iron, perhaps we can get the plankton to "bloom", suck up all the carbon and then sink to the bottom, taking the greenhouse gases with them.  The colour picture hereabouts shows a satellite view of an artificial bloom created by adding iron to the ocean.  It was actually a neat idea, except I could never shake off the feeling that the stuff would resurface one day and that it was just delaying the inevitable; it depends to some degree on whether the sunken material gets buried on the bottom or not, I guess.

Well, the idea recently received another blow; a new paper in PNAS reports that the sort of plankton that bloom after iron fertlisation are the same ones (Pseudonitzschia ) that produce domoic acid, a nasty toxin that causes horrible problems as it accumulates higher up the food chain, especially in sea lions and other marine mammals.

Marine mammals are kind of a sacred cow in biology, so my guess is that that will be that for iron fertilisation.  Ironically enough, the whole problem with domoic acid in the oceans, which is a relatively new phenomenon, may have climate change as its root cause anyway - blooms of Pseudonitzschia are supposed to have increased in frequency and intensity because of environmental changes.  You can't win, sometimes.

Saturday
Dec192009

Lazy SCUBA divers - pushing back the frontiers of climate science since 1970

Confused?  Read on...
Australia's CSIRO (the primary government-funded scientific research body; the kool kids say it like SIGH-row) has taken possession of a SCUBA tank last filled by its owner, a Mr. J. Allport, in 1968.  This may represent among the oldest clean compressed air currently available, and the boffins at CSIRO (one such boffin shown below), hope to use the contents to extend the directly-measured CO2 record back a few more years.  This would help improve the quality of climate data just a teensy bit more.  Admit it, that's kinda awesome.

I should call them. I'm pretty sure I've got a ham sandwich from 1982 somewhere in the attic; that must be useful for something...

Friday
Dec182009

Its a watery world

Its often said that Earth is 70% covered in water, but what if it were 100% covered (and not in the cheesey Kevin Costner way)?  And what if it were 6-7 times larger than it is?  And what if that ocean somehow remained liquid at 200°C...

Wait, what?  200 degrees??!

These are the properties of the latest "exoplanet" to be discovered, by a team at UC Santa Cruz.  An exoplanet is simply a planet in another solar system, and these days there's a veritable flurry of them being discovered.  This latest one in the Ophiuchus system about 42 light years away is the wateriest world yet found and, as far as we know, water is a prerequisite for life, or at least life as we know it.  At 200 degrees its hard to imagine, but with over 400 planets discovered lately, it seems inevitable that the discovery of an earth-like planet - with an earth-like ocean -orbiting a sun-like star is just a doppler shift away.

It doesnt seem that long ago that the idea of planets circling other suns was considered implausible

Friday
Dec182009

Try fitting *this* into a bedside lamp

Work reported in Nature today from a presentation at the annual AGU meeting shows easily the deepest underwater volcano ever filmed.  The eruption was filmed from a remote submarine at 1200m depth - far more than the previous 500m depth record - and shows lava bursting out onto the sea floor.  The discovery helps scientists understand how pillow basalts form and how sea floor materials are added to the oceanic crust.

Its hard to imagine how extreme that process is.  We're talking hot enough to melt lead, at pressures that would turn a styrofoam cup into a thimble!

Thursday
Dec172009

The front fell off...

I get sent this ALL the time.  As an Aussie, people think I might appreciate the joke, or, alternatively, want to deride an example of Australian politics.  I gotta tell the latter folks - its SATIRE.  Clarke and Dawes have had a spot on ABC's (thats AUSTRALIAN broadcasting corporation) "7:30 Report" every Friday for yars.

Its bloody funny though...

Thursday
Dec172009

Its a boy!

Congrats to the folks at Shedd Aquarium on the birth of a baby beluga whale - one of my personal favourite species (you will never meet a sweeter disposition in all the oceans).   Tell me this isnt the cutest little grey slug on the planet.

The little fella was born head first, which makes great sense for humans - where taking that first breath of fresh air is just a birth canal away - but not so great for whales, where you have to hold your breath until the rest of you comes out, before rushing to the surface.  In whales, such a head-first birth is considered a breech birth.  Nonetheless, he's apparently doing just fine.

He'll be grey for the first couple of years of life and then gradually get ever whiter, until he earns the common name for the species: "beluga" is Russian for white (and is actually pronounced more like b'loo-HA, with the H way in the back of the throat)

Thursday
Dec172009

Giant iceberg threatens Australia

Sounds odd right?  I mean, the sunburnt country - itself "adrift" in the southern oceans - on a collision course with a giant chunk of ice?  And yet, thats exactly the scenario unfolding off SW Western Australia.  Supposedly it broke off the Ross ice shelf, one of the largest on the planet.

The people in Perth could make a lot of gin and tonics...

Tuesday
Dec152009

Feral fish

No, not the long-haired hippy type, I mean those that are not indigenous to a habitat.  USGS and NOAA just co-published a pictorial guide to the non-native fishes of Florida.  This is doubtless part of the heightened awareness of this problem in US waters and, indeed, worldwide.  Lord Robert May recently cited invasive alien species - along with climate change, over-exploitation, and habitat destruction - as the most important causes is species extinctions in the biodiversity crisis.  It seems marine species are not immune to this effect; even though the diversity-stability hypothesis predicts that reefs ought to resist invasions.

My PhD thesis was about what happens to the parasite fauna when a fish gets introduced to a new habitat, so this subject is close to my heart.  To learn more, read about the subject as reviewed by my colleague Mark Torchin here:

Tuesday
Dec152009

Octopus using tools

I couldn't let this go by.  My wife is something of a behavioural expert and a very good animal trainer, and we have often discussed how intelligent octopus are.  In that respect this isn't news, but the tool use is pretty cool and very exciting for behavioural scientists, what with them being invertebrates and all (the octopus that is, not the scientists...).