Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Friday, January 6, 2017

Realignment in Asia

Last month, China seized an American drone operating in international waters some small distance from Subic Bay, in the Philippines. China returned the drone shortly thereafter. There was some small amount of diplomatic ranting over the incident, but these things tend not to escalate.

They have been going on for a long time. In the 1980s, Russian ships routinely stole equipment that had been deployed by Canadian research vessels in Canadian waters, most of which were only doing innocuous things like measuring salinity, temperature, and the speed of sound in the water column, much as the Americans' drone is reported to have done.

Of course, even innocuous oceanographic data can have geopolitical implications. There is a lot of speculation that the Chinese were afraid that the drone was to collect information on Chinese submarines. I'm going to go with the American story here--that it was to collect oceanographic information. That doesn't necessarily mean the data was not detrimental to Chinese interests. The question is, what are the Chinese interests?

. . . . . . . . . . . . .

On the Grand Banks, we went from station to station, lowering an instrument at each one, which would be anchored in place. When it came time to recover them, the ship would emit an acoustic signal, which would trigger a cable release and the instrument (which was buoyed) would rise to the surface for collection. On our perambulations, we noticed one or more Russian ships heading to our previous station. When the time came for collection, all the instruments were gone. The Russians had triggered the cable releases and scooped them all up. Rather, that was our interpretation--we weren't close enough to see for certain that they had done this, as the stations were kilometres apart. But no other ships were operating in the area.

We were conducting acoustic surveys as well, including sidescan sonar swaths for mapping the seafloor, as well as profilers and depth sounding. I noticed a number of submarine channels on the Banks--basically underwater fjords--and also noted that their geometry precluded them from being accurately mapped with the instruments we had. In fact there was nothing that we had in Canada that could have done it back in the day, because the issue was not a technical one--it was due to the separation between the instruments we were using and the seafloor. The limitation of standard methods for mapping steeply dipping structures was a significant part of my thesis that I wrote at the time.

In those days, instruments were towed--the umbilical was necessary for power, but towing was difficult from a surface ship through a narrow, and very deep canyon. Particularly when the cost of the instrument was high, and they tended to blow up due to the stresses upon contact with the seafloor. At one time, we had had an instrument that could be towed at a much greater depth, but (as I was told) the Russians stole the prototype in 1981 as it was being deployed, and for whatever reason, the Canadian company that made it didn't make another. (note: I have never found any independent corroboration of this story!!)

Anyway, what could be more innocent than mapping the ocean floor? Well, it turns out that our inability to map these structures properly meant that things near the bottom of the fjords were undetectable from near surface. In those days, antisubmarine detection would be via near-surface towed sonar, which would be ineffective here. Of course, there were other methods that could be used instead, but as long as we Canadians remained ignorant of the existence of these underwater fjords, we would not have the equipment ready to scan them. Does it mean the Russians were preparing an attack? (Probably not--but maybe they would simply like to be the only ones with this information, just in case). Or maybe the Russians were just short of equipment?

There can be a geopolitical element to even innocuous data collection from the seafloor. What threats might the Chinese have inferred from American drones in the South China Sea?

This article suggests the Chinese are worried about Americans tracking their subs. Possible. It's also possible that the Americans are planning for some bit of nastiness involving the Philippines, particularly after Philippine President Duterte's shift towards China. Or maybe they just want the information just in case.

Sometimes, moves like this are meant to send a message. The Americans may want the Philippines to know they are studying approaches to their coastline. The Chinese may want the Americans to know that they are willing to support their new friends.

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