Question

types of glaciers
continental glaciers
a continental glacier flows outward from a zone of accumulation to cover a large part of a continent. if the process could be speeded up, it might resemble what pancake batter looks like as it is poured onto a griddle. ice sheets that are several kilometers thick now cover most of greenland and antarctica. scientists have studied both regions to gain an understanding of ice caps and how they flow outward and down to the oceans. ice flowing into an ocean breaks away from the main body of the glacier to float away as icebergs. because ice is less dense than water, icebergs do not sink. icebergs from greenland and antarctica are large enough to pose a threat to the shipping industry. a number of vessels, for example the titanic, have sunk due to damage from collisions with icebergs. fortunately, icebergs break up and melt before they can invade most ocean areas.
valley glaciers
once permanent ice has formed atop mountains, it begins to flow downhill under the influence of gravity. valley glaciers, which begin high in mountain areas, flow from the high ice fields through valleys to lower elevations. most valley glaciers descend to an elevation where it is warm enough to melt the ice as quickly as it advances. if the ice in the glacier is moving forward at a rate of 1 meter/day, but the ice is also melting back 1 meter/day, the front of the glacier will not appear to move. this is known as a dynamic equilibrium because the rate of flow and the rate of melting are in balance. even though the end of the glacier may be in the same place from year to year, the ice is, in fact, constantly moving downhill. ice in a small glacier may advance only a few millimeters a day while larger ones may advance a few centimeters a day. as gradient and volume affect the speed of water in rivers, they also influence the speed of ice flow in glaciers. also, like the water in most rivers, ice moves fastest near the center and near the surface of a glacier.

1. what is the main difference between a continental glacier and a valley glacier?

Explanation:

The text describes continental glaciers as flowing outward from a zone of accumulation to cover a large part of a continent (e.g., Greenland and Antarctica). Valley glaciers, on the other hand, form on mountains, flow downhill under gravity through valleys, and often reach an elevation where melting balances forward movement. The key difference lies in their geographical location and flow patterns—continental glaciers cover large continental areas, while valley glaciers are mountain - originated and flow through valleys.

Answer:

The main difference is that continental glaciers flow outward from a zone of accumulation to cover large continental areas (e.g., Greenland, Antarctica), while valley glaciers form on mountains, flow downhill through valleys due to gravity, and often reach an elevation where melting and forward movement are balanced.