An interesting take on blues and greens

I stumbled across this today. Colours and how we perceive them never ceases to fascinate me.

As a tangent: I realize it has been more than two months since I've written anything, work on another project has left me exhausted.

The case of the drowning crickets

A firebelly toad waiting for a cricket

Our aquatic tank contains many firebelly toads, and each one of them is a voracious cricket eater. A few large rocks in the tank create an island, surrounded by open water. When we place crickets on the rocks, a significant portion of them fall into the water staying there until they drown (or until we rescue them and put them back on solid ground). Are cricket brains so tiny that they don’t realize they can’t breathe, and so don’t pull themselves out of the water, or is something else going on?

I found a nice explanation in an essay by J.B.S. Haldane (1892-1964) ‘On Being the Right Size’:

There is a force which is as formidable to an insect as gravitation to a mammal. This is surface tension. A man coming out of the bath carries with him a film of water of about one-fiftieth of an inch in thickness. This weighs roughly a pound. A wet mouse has to carry about its own weight in water. A wet fly has to lift many times its own weight and, as everyone knows, a fly once wetted by water or any other liquid is in a very serious position indeed. An insect going for a drink is in as great danger as a man leaning out over a precipice in search of food. If it once falls into the grip of the surface tension of the water - that is to say, gets wet - it is likely to remain so until it drowns.

I often swim at lunch. When I’m done I haul myself out of the water and head to the showers without a second thought for the amount of pool water I’m carrying around with me. It’s lucky for me that my size makes me immune to the same surface tension that drowns the unfortunate crickets.

As a tangent: I found an online copy of Haldane's essay here - it's worth reading and not too long.

Floating Trees

A tree in the forest near my home

Years ago I read C.S. Lewis’s Space Trilogy since I had enjoyed his The Lion, The Witch and The Wardrobe series as a kid. The Space Trilogy books were too weird for me and I can’t remember if I finished all three. What does stick in my memory is one of the settings (on Venus I think, but I could be wrong). The main character ran across surreal floating islands coated in trees and surrounded by water. The movie ‘Avatar’ also brought us tree covered floating islands (this time floating in the air due to a ‘flux vortex’), but the strangest trees I’ve come across are floating on glaciers and they’re real.

A while back, I went to a talk by Hig about his trek with his wife, toddler and baby across Malaspina Glacier (find their blog here). They lived in the wild for two months. Clearly they are somewhat crazy - in a fantastic way, I wish more people took their kids into nature that way. From the video and photos clearly the kids had an awesome time.

Malaspina Glacier sits by the ocean on the southern reaches of Alaska reaching 600m thick in places and covering an area of 3,900 square km. Like many glaciers, this one is shrinking however the most striking feature to my mind is that in places trees grow on it. Trees growing on top of ice - how fabulous is that! Even assuming there is some sort of soil layer buffering the roots from the ice.

Are there other glaciers out there with trees growing on them?

a porpoise for a trip

The picture of the turtle I took was
blurry - so here's my lunch instead

This morning I went on a short road trip to drop off a harbour porpoise and pick up an olive ridley sea turtle from the Pacific Biological Centre - a trip that took two hours one way. Both animals had been found dead, frozen and put into scientists hands.

Olive ridley’s are the most abundant of the sea turtles. Unfortunately, their numbers are declining putting them at risk of extinction like all the other sea turtles. Years ago, I saw a live one on a beach in Costa Rica that came ashore to lay eggs - we moved along quickly to avoid disturbing her. It was night and to me she seemed huge as she hauled her mass up the sandy beach, however, they’re small compared to other sea turtles.

The sea turtle we picked up today ventured too far north as they normally live in tropical waters - in fact, turtle was the first olive ridley ever found here. Cold blood in cold water meant the animal probably was moving pretty slow. It was found on a beach in Toffino after it was too late to help. Why it came this far north we don’t know.

I’ll write more about the turtle shortly, as I’ll be helping at the museum to preserve it.

talks about climate change

I'm still at the Ocean Sciences Meeting. So far, every session of talks I attend are in rooms with a capacity for a great number more people than show up. As I look around, there is always an uneven sprinkling of people throughout the room.

Wednesday, 22 February 2012 - Day 3

An interesting point came up that I hadn’t considered: coral reefs are studied with much more frequency than the equally (or more so) common eelgrass beds. I wonder if the colourful fish make are simply more appealing? Although, fascinating creatures live in eelgrass.

One of the sessions I attended was titled ‘Imaging the Ocean Interior’ - I was excited about one of the last talks that hinted at exploring underwater ice caverns with acoustics. Two of these talks focused on re-using the seismic survey data collected by oil and gas companies. This is data collected to look at what is beneath the ocean floor, but it can provides interesting information about the structure within the water column such as internal waves and boundaries between layers.

A cool use of acoustics is looking at really small things. One group is able to ‘see’ targets down to 0.8 mm in size. This same group has simultaneously developed an optical system, essentially an underwater microscope, that sees to 25 micrometers giving a clear view of phytoplankton. Both these techniques can be deployed into the ocean, reducing the need to bring samples back to the lab.

The afternoon wasn’t without disappointment. The under ice exploring talk focused on a project they wanted to do, not one already completed. I’ll have to attend the next conference to see their results.

Thursday, 23 February 2012 - Day 4

Melting glaciers are an iconic symbol of climate change

- J. Bamber, Nature, February 2012

Another early start with ‘Dynamics of Fjords and High Latitude Estuaries’. A lot of focus is being put on the fjords in Greenland because of the melting ice sheet there. As this ice sheet melts it adds about 0.09 mm each year into the oceans contributing to rising sea levels. The majority of fresh water released from a glacier is due to calving icebergs and melting from beneath the glacier that passes over sea water, only a small portion if due to run off. Increased fresh water can change the dynamics of fjords making an interesting basis for a scientific study.

As a tangent - I wish I brought my camera so I could include some pictures!