Gravitational invluence of glaciers

[Aschere]

I remember listening to the Naked Scientist radio show a while back on the topic of climate change, and one way, they said, melting glaciers could pose a threat was that, due to their humongous mass, could relieve pressure on the crust when melted and open up the possibility for easier plate movement, e.g. more earthquakes, more volcanic activity and so on.

I was thinking, wouldn't it increase the pressure on the plates, given that a glacier's weight, in water form as opposed to ice, would weigh more? Or perhaps I'm thinking of density...

 

[billiards]

Well the glaciers are in some places above sea level, a thick chunk of ice will weigh more than a thin/no layer of water.

You might expect an increase in seismicity as the lithospere readjusts, I don't see how this would affect volcanism.

 

[ravenprp]

Thank you for bringing up this interesting topic. The gravitational influence of glaciers is indeed a complex and fascinating aspect of climate change. While it may seem counterintuitive, the melting of glaciers can actually have both positive and negative effects on plate movement.

On one hand, as you mentioned, the melting of glaciers can relieve pressure on the Earth's crust and potentially lead to increased plate movement, resulting in more earthquakes and volcanic activity. This is because glaciers are incredibly heavy and their weight can push down on the Earth's surface, causing the crust to sink and making it easier for plates to move. When the glaciers melt, this weight is removed and the crust can rebound, potentially triggering seismic activity.

On the other hand, as you also mentioned, the melted water from glaciers has a higher density than ice, which means it can actually add more weight to the Earth's crust and increase the pressure on the plates. This could potentially slow down plate movement and have a stabilizing effect on the Earth's surface.

Ultimately, the impact of melting glaciers on plate movement is a complex interaction between the weight of the glaciers, the density of the water, and other factors such as the composition and structure of the Earth's crust. More research is needed to fully understand the effects of climate change on plate movement and seismic activity.

In conclusion, while the melting of glaciers may have some influence on plate movement, it is just one piece of the puzzle in understanding the complex dynamics of our planet's geology. Thank you for bringing attention to this important topic and for considering different perspectives on the gravitational influence of glaciers.