Question

Studies have shown that during the lce Age the margins of some ice sheets advanced southward from the Hudson Bay region at rates ranging from about 50 to 320 meters per year. a. Determine the maximum amount of time required for an ice sheet to move from the southern end of Hudson Bay to the south shore of present day Lake Erie, a distance of 1600 kilometers. b. Calculate the minimum number of years required for an ice sheet to move this distance.

Short answer

a. Maximum time is 32,000 years. b. Minimum time is 5,000 years.

Step-by-step solution

Convert Distance to Meters

First, we need to convert the total distance the ice sheet traveled from kilometers to meters, as the advancement rates are given in meters per year. There are 1000 meters in a kilometer, so the distance in meters is:\[ 1600 \text{ km} \times 1000 = 1,600,000 \text{ meters} \]

Calculate Maximum Time Using Minimum Speed

To calculate the maximum time required, use the slowest speed of the ice sheet, which is 50 meters per year. The formula to find time is:\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]Substitute the values:\[ \text{Time}_{\text{max}} = \frac{1,600,000 \text{ meters}}{50 \text{ meters/year}} = 32,000 \text{ years} \]

Calculate Minimum Time Using Maximum Speed

To find the minimum number of years required, use the fastest speed, which is 320 meters per year. Use the same time formula as before:\[ \text{Time}_{\text{min}} = \frac{1,600,000 \text{ meters}}{320 \text{ meters/year}} = 5,000 \text{ years} \]

Key concepts

Glacial Movement

Glacial movement is a fascinating Earth process that unfolds over thousands of years. This involves massive glacier flows, primarily during the Ice Age, when sheets of ice moved across continents. The movement is driven by gravity, with ice slowly deforming under its weight and pressure.
Unlike liquid water, which flows quickly, glaciers move at a slow and steady pace, creeping over the landscape. This movement can be influenced by various factors such as changes in climate and the underlying terrain.

• Ice flows from regions of high accumulation to areas of melting or calving.
• Glaciers carve out valleys and reshape landforms as they move.

Understanding glacial movement helps scientists interpret historical climate patterns and predict future changes.

Advancement Rate

The advancement rate of glaciers refers to how quickly they can move over a landscape. This is typically measured in meters per year. During the Ice Age, glaciers could advance at rates from 50 meters per year to as much as 320 meters per year.
These rates can vary immensely depending on several conditions, such as temperature, slope, and ice thickness.

• Slower rates often result from thicker ice or uphill terrain.
• Faster rates might occur on steeper slopes or where the ice is thinner and more fluid.

This concept helps us calculate how long it will take a glacier to travel a specific distance, as seen in historical analysis of glacial movements.

Hudson Bay

Hudson Bay was a crucial area during the Ice Age as it was a central point for glacial activity. This large body of water in northeastern Canada was covered by the massive Laurentide Ice Sheet.
As glaciers expanded southward, they originated from areas like Hudson Bay, making it a significant part of glaciological studies.

• The Ice Sheet over Hudson Bay was massive, influencing global sea levels.
• Understanding this area helps explain how glaciers shaped North America's geography.

Today, Hudson Bay's history gives insight into past climates and the dynamics of ice sheet behaviors.

Lake Erie

Lake Erie, one of the Great Lakes, was heavily impacted by glacial movements during the Ice Age. The retreat of glaciers after advancing past modern-day Lake Erie left behind drastically transformed landscapes.
The south shore of Lake Erie marks an important reference point for studying glacial advancement from the Hudson Bay area.

• Glacial movements shaped the lake's basins and surrounding regions.
• The deposited sediments influenced the area's ecology and topography.

By examining how ice once covered this region, scientists gain insights into ancient environmental conditions and the power of glacial forces.

Distance Conversion

Distance conversion is a simple yet essential mathematical process, especially when dealing with different units of measure. In the context of glacial movement, it's important because advancement rates are often given in meters, while distances might be reported in kilometers.
To convert a distance from kilometers to meters, multiply the number of kilometers by 1000 (since 1 km = 1000 meters).

• Example: 1600 km converts to 1,600,000 meters.
• This conversion allows for consistent units in calculations for time and speed.

Understanding and applying distance conversion is crucial in accurately computing the time required for glacial movements.