Monday, February 23, 2009

Celebrating the Sunsets

Due to popular demand, I've decided to put up a collection of my sunset pictures. About 1 hour before the sun sinks below the horizon, a small group of boat-dwellers and marine mammal personnel gather up on the whale-watching tower and enjoy the cool breeze of early evening. Most days, the sky is filled with puffy white clouds, which reflect beautiful shades of pink and orange as the sun disappears behind the ocean.

On the clear days, we wait in anticipation hoping to catch the flash of green just as the sun sets. I haven't seen the flash yet, although I have seen a faint green halo around the sun as it began to set. A couple of the guys claim that they saw this elusive flash a few days ago; and of course, they then tried to make us all horribly jealous. Although the sunrises I saw were beautiful, I think that I like the sunsets even better. I hope you enjoy the pictures!

Friday, February 20, 2009

The Night Sky

Since the moon isn't full anymore, the rest of the night sky is absolutely brilliant. On a clear night, there are thousands of stars littered across the sky. In the past week, I've seen some of the most amazing night skies of my life.

Since I switched from the night shift to the day shift, I was able to see the planet of Venus sinking to the west, an hour or so after sunset (~8-9 pm). Venus is only ever visible in the night sky just after sunset or just before sunrise, because it's closer to the sun than the Earth is. Unfortunately, the only time I was able to get a picture of it with my camera was shortly after sunset; compared to the sun, it is quite dim. This picture is from February 21st, and Venus is the dot in the top right of the picture (you have to look very hard to see it).

At first, the southern sky was so foreign to me that I didn't recognize any of the stars except those in the constellations of Orion and Canis Major - which can also be seen in the northern sky. But after some help from the guys on the bridge (and a neat navigation program on their computer), I've finally seen the Southern Cross that everyone mentions. Some other familiar favorites are the Pleiades, and the Big Dipper. I didn't even think that I would be able to see the Big Dipper in the southern hemisphere, but early in the morning, part of it is visible just above the northern horizon.

It really isn't easy to pick out constellations, because there are thousands of stars in the sky. After a while, I became content to just lay on the picnic table on the deck or on the ropes in front of the bridge and watch the stars sway back and forth with the rocking boat. With a cool breeze and the sound of the waves crashing against the bow, it's quite possibly the best way to end the day.

Wednesday, February 11, 2009

Perfect Sunrises

One of the best parts about working from midnight to noon is that I have many chances to catch the sunrise. I think I have watched more sunrises in the past 3 weeks than I've seen in my entire life. And, as long as the sky isn't completely overcast, every sunrise is absolutely perfect. My favorite place to watch them is on the small piece of deck in front of the bridge, just behind the bow. A bunch of large, coiled ropes provide a pretty comfy seat, and the cool, humid breeze coming up over the bow is the best. If I wasn't so eager to watch the sun come up, I probably could take a pretty nice nap there.
I hope you enjoy these - I certainly did!

Saturday, February 7, 2009

Arc Welding

I learned arc-welding from some of the guys on the boat (Bern and Brian)! They made me wear a really nasty leather coat, huge leather gloves, and of course the large welding mask. Despite all of this protective gear, a spark still burned a perfectly round hole in my shoe, which I discovered the next day. As a souvenir, I welded my name onto a steel plate. In order to make it actually look good (ha!), Brian rounded the edges of the plate and then polished it up really nicely. I now have a 2 pound steel plate that I need to fit into my max 50 lb. baggage somehow on the way home!
I really enjoyed learning how to weld, and I wish there was more scraps of steel around that I could ruin!

Thursday, February 5, 2009

Cyclone "Hettie"

We are in the southern hemisphere, so we are in the middle of their tropical storm season. As I mentioned, we managed to finish deploying the seismometers just as the waters were starting to get choppy. I was pretty alarmed when there was a cyclone warning issued for all the Tongan Islands and Fiji - this being my first ever tropical storm ever. Luckily the storm wasn't large, and it didn't actually reach cyclone status until well to the south of us. Besides the rocking of the boat and the fact that we couldn't start the air-guns until the seas became calmer, the whole ordeal wasn't bad at all; in fact, it was sort of fun.

While out on deck earlier with the OBSs, I was able to experience waves crashing over the side of the boat and drenching us; that was fun and exciting. Also, I've never had the experience of feeling like I was going to get tossed out of bed. It's like having a dream about falling, except when you wake up, you realize that the bed actually is falling out from beneath you. The bouncing up and down of the boat felt a lot like a trampoline, and it was my favorite part of the weather. My second favorite part was the crazy rolling of the boat (tipping from side to side). I suppose it really isn't cool for all the belongings on your desk to get thrown onto the floor; but for me, it was pretty exciting. In close third was the weird combination of pitch and roll, which suddenly gives the spinning-room sensation - so far, this brought me the closest to losing my lunch. Unfortunately, the seas became choppy before we were entirely used to being on a boat in the first place, so most people had difficulty sleeping and some became sick. Now that it's all over, and we're no longer sleep-deprived and crabby, I'm going to go ahead and say that the whole ordeal was pretty cool.

Ocean-Bottom Seismometers

One of the best parts of my time on the boat (so far) was deploying the 59 ocean-bottom seismometers (OBSs). These instruments measure vibrations in the Earth, which are created by "air-guns" towed behind the boat. The bursts from the guns shake the crust beneath the water and the vibration moves outwards through the crust in all directions to the array of seismometers. The signals recorded by our seismometers can show hotter regions, where seismic waves travel slower, and colder regions, where the waves move faster. For this reason, our work out here in the back-arc basin is meant to "see" any hot regions beneath the surface, as we would expect to see in an active back-arc basin.

In order to get all of this data, we first had to send all of these seismometers (OBSs) to the seafloor. Each OBS has a sensor (the actual seismometer part), a data recorder (which records the data as a digital signal), a heavy weight, and empty glass spheres surrounded by yellow plastic. When the instrument is deployed, the weight drags it down to the seafloor. Then when the experiment is over, a signal is sent to the OBS, telling it to release the weight. After that, the OBS rises back to the surface, where we collect it. The OBSs were built mostly ahead of time, so as we cruised over the sites for the instruments, we were able to carefully drop it into the water and continue onward. We finished this stage in about 2-3 days - fortunately before Cyclone "Hettie" came our way!

Wednesday, February 4, 2009

The Tongan Arc and the Lau Basin

The Tongan island arc is a series of volcanoes west of the main islands in the Kingdom of Tonga. They form because one crustal tectonic plate (the Pacific plate) subducts - is forced or pushed - beneath the other plate (the Australian). The subducted Pacific plate then sinks into the earth (into a layer called the mantle). The more populated islands of Tonga, to the east are not volcanically active. The Lau Basin is directly to the west of the Tongan island arc, over a feature called a back-arc basin. In this area, the crust splits apart and forms new rock when material deeper down flows upward, melts and erupts at the surface.

This is the region where we are spending ~45 days dropping seismometers to the seafloor and sailing back and forth in a grid pattern to collect sonar, seismic, gravity, and magnetic data. All of these geophysical techniques will help to map both the surface of the seafloor (the bathymetry) and the structure of the crust and upper mantle (the top 10-20 km of the Earth).

Monday, February 2, 2009

Learning to walk

The first three of four days, I had a regimented schedule of eating something every 2-3 hours to avoid sea-sickness. At the same time, I was trying to bring myself onto my ship schedule (working midnight to noon). Despite trying the Dramamine thing, I agree with my friend Patrick who says that the only way to prevent sea-sickness is to keep your stomach full; thus the gluttony. This seemed to be the only thing that worked, and I was a little concerned that I was going to gain a lot of weight from eating so much. Fortunately, the need for food seems to be passing, and I'm now eating regular meals... although I can't seem to pass up the ice-cream that is readily available at all times in the mess!

Walking on the boat is an entirely different story. I'm already pretty clumsy on land - regularly walking into walls and doors. The first couple of days on a boat were about twenty times worse. Imagine trying to open a heavy door and walk through while carrying a cup of coffee on a boat swaying from side to side. Then imagine being as graceful as me, and that should give you an idea of why I keep finding new bruises all over my arms and legs. After about a week of walking into walls and getting squashed in doors, I am becoming more agile, or at least I'm not worried about falling down the stairs anymore. I'm hoping that I might have finally gotten these "sea-legs" that everyone talks about!

My home on the boat! Left: My room (I got a zebra-print comforter)!
Right: Our common room