Question

Studies have shown that during the Ice 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

The maximum time is 32,000 years, and the minimum time is 5,000 years.

Step-by-step solution

Understand the Problem

We are asked to determine the maximum and minimum time it would take for an ice sheet to travel from the southern end of Hudson Bay to the south shore of present-day Lake Erie over a distance of 1600 kilometers.

Convert Kilometers to Meters

To determine the number of years, we need to convert the given distance from kilometers to meters because the rate of movement is given in meters per year. 1 kilometer = 1000 meters, so 1600 km = 1600 * 1000 meters = 1,600,000 meters.

Calculate Maximum Time

The maximum time required occurs at the minimum movement rate of 50 meters per year. Use the formula: Time = Distance / Rate So, Time = 1,600,000 meters / 50 meters per year = 32,000 years.

Calculate Minimum Time

The minimum time required occurs at the maximum movement rate of 320 meters per year. Using the same formula: Time = Distance / Rate So, Time = 1,600,000 meters / 320 meters per year = 5,000 years.

Key concepts

Ice Age

The Ice Age is a term used to describe a period in Earth's history when large parts of the planet were covered with ice sheets. This era is known as the Pleistocene Epoch, which occurred from about 2.6 million years ago to 11,700 years ago. During this time, temperatures were colder, and extensive ice sheets covered much of North America, Europe, and Asia. Scientists use evidence from geology, ice cores, and sedimentary records to study these icy periods.
One fascinating aspect of the Ice Age is how ice sheets moved. These massive bodies of ice advanced and retreated over time, reshaping landscapes. The movement of ice sheets was influenced by climate, geological features, and the Earth's orbit around the sun. Understanding these movements helps scientists uncover the history of our planet's climate and anticipate future climate scenarios.

Ice Sheets

Ice sheets are enormous masses of glacial land ice extending over 50,000 square kilometers. Presently, Greenland and Antarctica hold the only two ice sheets on Earth. Historically, during the Ice Age, vast ice sheets covered significant portions of the Northern Hemisphere, including areas now part of Canada, the United States, and Europe.
These gigantic ice formations flowed outward and moved incredible distances. Their movement is slow yet powerful over geological timescales. For instance, during the Ice Age, some ice sheets advanced southward from regions like the Hudson Bay. This movement can occur at rates ranging from a few dozen meters to hundreds of meters annually. This steady but powerful motion has the capability to carve out landscapes, form lakes, and dramatically reshape the Earth's surface.
For example, the advancing ice sheets have been responsible for creating features like the Great Lakes in North America. Understanding their dynamics is crucial for studying past climate changes and predicting future shifts in ice patterns due to global warming.

Hudson Bay

Hudson Bay is a large body of saltwater in northeastern Canada. Known for its unique geographic features, it is one of the largest bays in the world. During the last Ice Age, Hudson Bay was an essential center from which massive ice sheets originated. These ice sheets played a significant role in shaping the topography of North America.
Situated in a low-lying basin, Hudson Bay was formed by the immense pressure and weight of ice sheets that compressed the Earth's crust. When these ice sheets advanced, they moved southward from the Hudson Bay, influencing areas as far as the Great Lakes.
Today, Hudson Bay is still influenced by its glacial past. The land around it continues to rise slowly, a process known as "isostatic rebound," as the Earth's crust responds to the melting and reduced weight of the glaciers. This fascinating legacy reminds us of the profound impacts that ice sheets have had on the Earth's surface.

Geological Time

Geological time is a concept used to understand the vast history of Earth's formation and development, spanning billions of years. This extensive timeline is divided into several units such as eons, eras, periods, and epochs. One of these divisions is the Pleistocene Epoch, which included the most recent Ice Ages.
Unlike human timelines that span years or centuries, geological time covers millennia. Studying geological time allows scientists to track the Earth's changes through periods of cooling and warming, mountain formation, and significant biological evolution. It provides insights into shifts in climate and landscape over time.
The concept is vital because it contextualizes human existence as a tiny part of Earth's history. Understanding geological time helps scientists determine how current environmental changes fit into the Earth's natural cycles and how past climates have altered the planet's surface. Such knowledge is crucial for making informed predictions about future climate patterns and preparing for potential impacts on the environment and human life.