What looks like a pulse at 14ka is really the start of the interglacial which was interupted by the Younger Dryas. You're correct that it corresponds with what is thought to be a meltwater pulse which shut down the gulf stream causing a return to glacial conditions for about 1500 years.<quoted text>
I hadn't seen such a large spike like the Greenland core here ~14 Kya. Interesting that it may ROUGHLY correspond to Meltwater Pulse 1-A, when sea level rose ~20 meters in less than 500 years, or perhaps 200 years. I saw a recent studay reporting evidence in Tahiti that it was associated with a sudden ice shelf collapse in Antarctica.
That would have been interesting - world-wide tsunamis, probably in the hundreds of meters tall when they approached shorelines, leaving sea level permanently ~20 meters higher - all in just a matter of hours or days.
The same activity is seen in the antarctic but as with all ice core data is less prominent in the antarctic. What is interesting is that the antarctic leads the arctic, except in this case. This evidence is thought to indicate that the event that caused the Younger Dryas was indeed isolated to the NH and impacted global temps.
Some studies explore a exterestrial hit, comet is most often thought because of particulate matter found in the sediment of eastern canada. Which would have been a perfect spot for shutting down the gulf stream. That hypothesis is still under investigation.
Hadn't seen the antarctic ice shelf collaspe premise, you're right anything that big would have had major impacts.