Scientists have found a record of glacier advances in Mueller Glacier in New Zealand.
Click on image for full size
Image Courtesy of George Denton

Glacial Advances
News story originally written on April 29, 2009

Most of the world's glaciers are melting as the planet gets warmer. But a few, including glaciers south of the equator in South America and New Zealand, are growing larger. For the last 7,000 years, New Zealand's largest glaciers have often acted differently than glaciers in the Northern Hemisphere. This is a reminder that there are often regional variations in climate in different locations on the Earth.

Glaciers are extremely sensitive to changes in temperature and snowfall, which makes them helpful for studying past climate. But it is very difficult to determine the exact ages of glaciers from the past. One way to measure changes in glaciers is by studying the moraines, or rock deposits, that glaciers often leave behind when they begin to melt.

Scientists recently used a new method to learn the ages of the rocks in the moraines in New Zealand. This method is called cosmogenic dating, and it tells scientists exactly when the glaciers in New Zealand's Southern Alps began to melt. The scientists used this data to compare New Zealand's glaciers with glaciers in Europe. They learned that during the past 7,000 years glaciers in New Zealand were very large at times when the glaciers in the Swiss Alps and Scandinavia were melting due to warm weather.

Overall, glaciers around the world have been melting since about 1860, except for a brief advance of the glaciers in Switzerland in the 1980s, in New Zealand in the late 1970s through today, and in a few other places. Changes in wind and sea surface temperatures are thought to be causing these regional changes. Though it is wet in New Zealand right now, scientists think the climate is expected to swing back to a warmer, drier phase in the next few years, causing the glaciers to melt once again.

Last modified May 27, 2009 by Becca Hatheway.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Glaciers and Ice Sheets

For a glacier to develop, the amount of snow that falls must be more than the amount of snow that melts each year. This means that glaciers are only found in places where a large amount of snow falls each...more

Global Warming: Scientists Say Earth Is Heating Up

Earth’s climate is warming. During the 20th Century Earth’s average temperature rose 0.6° Celsius (1.1°F). Scientists are finding that the change in temperature has been causing other aspects of our planet...more

Wind

Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more

Triggers of Volcanic Eruptions in Oregon's Mount Hood Investigated

Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. "The data will help give us a better road map to what a future...more

Oldest Earth Mantle Reservoir Discovered

The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core, and makes up about 84 percent of the Earth's volume. The mantle is made up of many distinct portions or...more

It’s Not Your Fault – A Typical Fault, Geologically Speaking, That Is

Some geologic faults that appear strong and stable, slip and slide like weak faults, causing earthquakes. Scientists have been looking at one of these faults in a new way to figure out why. In theory,...more

Lower Solar Activity Linked to Changes in Sun's Conveyor Belt

The sun goes through cycles that last approximately 11 years. These solar cycle include phases with more magnetic activity, sunspots, and solar flares. They also include phases with less activity. The...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA