Home

Going to San Francisco

Every year, in fall, thousands of geophysicists invade the city of San Francisco for the week-long conference of the American Geophysical Union (AGU).  The 2010 meeting took place in the heart of San Francisco in the Moscone Center (Figure 1) from December 13^th-17^th.  It was attended by over 16,000 people studying a wide range of topics from Biogeosciences to Aeronomy; creating something of interest even for someone with very little knowledge in geophysics.  Scientists could present either a 12minute oral presentation or prepare a large poster summarizing their work.  Presentations and posters were arranged in sessions based on their main topic, but with such a large gathering, many sessions occur at the same time and one had to choose.
Figure 1: The Moscone Center in San Francisco where most of the presentation for the Fall Meeting of the American Geophysical Union took place.

For me, the Ocean Science sessions were of particular interest and even included a few presentations on the ecology of hydrothermal vents. NEPTUNE Canada representatives, including

Mairi Best,

Martin Heesemann,

Steve Mihaly,

Marjolaine Matabos,

Maia Hoeberechts

and myself, presented posters in a variety of sessions (Figure 2).  Topics included:

• Introducing the network infrastructure
• Analyzing data gathered via boreholes and seismometer
• Studying linkages between surface and bottom processes
• Studying ecological processes on the seafloor using cameras

Figure 2: Steve Mihaly and Martin Heesemann presenting their posters during the Thursday morning sessions.

My poster focused on presenting how camera systems can be used to examine the response of organisms to changes in their environment (Figure 3).  Particular focus was given to hydrothermal vent communities, but insights gained with other systems (e.g. the black and white video cameras installed in Barkley Canyon and the Tempo-mini system previously tested in Saanich Inlet) were also presented.  The potential for high sampling resolution allows researchers to observe fast processes such as biological interactions and behavioural activities.  NEPTUNE Canada’s planned long-term observation series will also enable monitoring of spatio-temporal shifts in community assemblages, while co-located sensors ensure that the environmental fluctuations responsible for those changes can be characterized.  Real-time event detection and interactive response will make it possible to describe recovery from natural disturbances common in highly dynamic seafloor environments. 

Figure 3: Illustration of the poster presented in the ‘Deep-Sea Hydrothermal Systems: New Knowledge From New Discoveries and New Technology’ session.

Overall, this meeting was a great opportunity to present results obtained through the NEPTUNE Canada observatory as well as explore future opportunities for collaborations and the addition of new instruments.

Waiting on Weather

Fall and winter in the North Pacific is a time for strong winds, big waves and storms.  Low pressure systems originating in the west cross the Pacific and move toward the Bering Sea.  When doing ship-based research, deploying and recovering instruments over the side with a crane is a tricky operation even in calm weather; attempting it in rough weather is simply not worth the risk.  Hence, monitoring the weather is a crucial part of offshore operations. 

National weather services such as Environment Canada have prediction centers whose models generate forecasts and create updated weather maps many times a day.  On the upper map below (Figure 1), the L represents the center of a low pressure system (usually accompanied by bad weather) and the H, a high pressure one.  The contour lines (isobars) indicate regions of equal air pressure; stronger winds occur in areas where the pressure gradient is larger and the isobars are closer together.  On the lower map below (Figure 1), the arrow-like symbols (Figure 2) illustrate wind speed and direction.  The end where the “point” should be shows the direction toward which the wind blows.  The “feathers” indicate its force, a triangle if 50knots, one full line is 10knots and a half line is 5knots.  In a low pressure system, the wind moves counter clock wise (at least in the northern hemisphere); the air rises in the atmosphere where it eventually cools down and its water content condenses forming clouds.  On that same map, the regions of different colors indicate wave height.

Figure 1: Forecasted weather map for Canada for December 1^st 2010 showing the location of low and high pressure systems (top). Forecasted sea state map of the Northeast Pacific for the same date (bottom).  Both maps were created by Environment Canada.

Figure 2: Symbol used to indicate wind speed and direction on a weather map.  In this example, the symbol shows wind blowing at 45knots, roughly to the east.

In the case of operations involving remotely operated vehicles or manned submersibles, when the waves are higher than 3meters or the wind is blowing above 25knots, diving is not possible.  Research cruises usually lose at least a few days due to bad weather and fewer of them are scheduled in the winter months.  The weather in the Northeast Pacific can also change very quickly.  Sometimes a dive can start, but has to end early because the wind is picking up and the swell is expected to follow.  In the case of deep sites like Endeavour, contingency time allowing for the two hour long ascent also needs to be factored in; making the planning of operations with respect to weather somewhat of an art.  Once deployed, instruments connected to cabled observatories will not be affected by rough weather; this continuous presence is one of the main advantages of this sampling tool.  But after the storm the nice weather eventually comes back and we have beautiful days where the ocean looks like a mirror (Figure 3).

Figure 3: The end of a beautiful day aboard the R/V Thompson