Why aren't you asking about those short term disturbances? That is the leading hypothesis of the cause of the Younger Dryas, a ~1000 year long interval at the end of the last glaciation when the Earth got very, very cold. This hypothesis claims that a temporary diversion of the cold meltwaters of Lake Agassiz to the St. Lawrence Seaway shut down the thermohaline circulation.Czcibor said:Yes, curious about that.
(No, I'm NOT asking about some short term disturbances when glaciers were melting, but whether with lower temperature and part of continental shelf above water caused the currents to change their direction)
D H said:Why aren't you asking about those short term disturbances? That is the leading hypothesis of the cause of the Younger Dryas, a ~1000 year long interval at the end of the last glaciation when the Earth got very, very cold. This hypothesis claims that a temporary diversion of the cold meltwaters of Lake Agassiz to the St. Lawrence Seaway shut down the thermohaline circulation.
Back to your question,Czcibor said:Yes, curious about that.
(No, I'm NOT asking about some short term disturbances when glaciers were melting, but whether with lower temperature and part of continental shelf above water caused the currents to change their direction)
Abstract
The Younger Dryas cold event is a relatively unique feature of the last deglaciation when compared to previous deglaciations, suggesting a unique trigger rather than the commonly held forcing mechanism of North American freshwater routing to the North Atlantic. Here, I compare the last (T-I) and penultimate (T-II) deglaciations and provide new support for the argument that the lack of a Younger Dryas-like event during T-II is due to the rapidity of Northern Hemisphere ice sheet retreat under greater boreal summer insolation forcing. Faster ice retreat suppressed Atlantic meridional overturning circulation (AMOC) until near the end of T-II, while during T-I AMOC increased relatively early. During T-I, the eastward routing of freshwater that caused the Younger Dryas happened after AMOC resumption, whereas during T-II this routing occurred prior to the resumption of AMOC. Thus the increased flux of freshwater to the North Atlantic during T-II had little effect on AMOC, explaining the lack of a Younger Dryas-like climate oscillation during this deglaciation.
The ice age had a significant impact on the direction of oceanic currents. As glaciers formed and expanded, they caused sea levels to drop and altered the shape of continents. This change in topography affected the flow of ocean currents, causing them to shift in direction.
While there is evidence that oceanic currents may have influenced the timing of the ice age, they were not the main cause. Other factors such as changes in the Earth's orbit and atmospheric composition played a larger role in the onset of the ice age.
The altered direction of oceanic currents had a major impact on marine life during the ice age. As currents shifted, they brought different nutrient-rich waters to various regions, affecting the distribution and abundance of marine organisms. Some species were able to adapt to these changes, while others became extinct.
Yes, we can still see the effects of the ice age on oceanic currents today. The altered topography and circulation patterns that were established during the ice age continue to influence currents and ocean circulation patterns. However, human-induced climate change is also causing significant changes in ocean currents.
Yes, there are many ongoing studies and research being done on the relationship between the ice age and oceanic currents. Scientists are using various methods such as sediment cores, computer simulations, and satellite data to better understand how the ice age impacted ocean currents and how those changes continue to affect our planet today.