How does an ice age affect landscapes?

Answer 1

The Ice freezes the landscapes so it can break easily. The landscape can break easily since it becomes ice.

Not quite, if you define the landscape as the rocks that form it. Freezing water within cracks in the rock will split it eventually, but the primary effect is glaciation. Glaciers scour out huge U-section valleys and deposit the spoil as moraines or various kinds, erratics, sheets of till, outwash plains and on the sea-bed, huge sediment fans and drop-stones. They also leave assorted traces of their passing such as striations and plucking.

The moraines can also create natural dams ponding water to create lakes that may eventually drain as the river incises the moraine but still leaves evidence of its existence as old shore-lines.

Ice-dammed lakes at altitude can overflow through cols, cutting distinct notches in the ridge.

In slightly less icy conditions, snow can create nivation hollows in the flanks of Chalk hills: the chalk is slowly dissolved by meltwater under remnant snow-patches usually on the North-facing (in Northern hemisphere) flanks.

The changes of sea-levels consequent on glacial and interstadial periods leave tell-tales such as drowned river valleys and raised beaches.

Following ice-retreat, isostatic rebound of an area of continental crust that had been depressed by the sheer weight of a deep ice-cover can locally activate faults, creating irregular profiles in rock surfaces and ridges, with accompanying earthquakes. Those in Norway continued into historical times but the rebound there has more or less ended.

As a handle on the weight of an ice-cover on the landscape, that over Scandinavia in the last glaciation reached 3km thick, but if we take a mean cover of only 2km, and the density of ice as 0.9 Tonne/m3, that gives a mass of

0.9 x 2 x 103 x 103 x 103 Tonnes per square kilometre,

= 1.8 x 109 T/km2

The area of the Scandinavian Peninsula + that of Denmark is about 820 000 sq.km. so an ice-sheet of mean thickness 2km over that lot will weigh:

1.8 x 8.2 x 109 x 105 Tonnes

= 1.48 x 1015 tonnes.

Or if you prefer, getting on for fifteen million million Tonnes of ice.

No wonder that part of the European Plate was depressed significantly.

Answer 2

During an ice age, glaciers advance and retreat, carving out deep valleys and fjords, smoothing out surfaces, and depositing large amounts of sediment. This process can reshape the landscape, creating new landforms such as moraines, drumlins, and eskers. Additionally, ice ages can result in changes to ecosystems and biodiversity as species adapt to the changing climate and geography.