Malaspina Glacier

The Malaspina Glacier is a massive ice formation located in southeastern Alaska. It holds the title of the largest piedmont glacier in the world. A piedmont glacier is a specific type of ice flow. It occurs when glaciers spill out from mountains onto a flat coastal plain.

This glacier sits at the head of the Alaska Panhandle. Its total area is approximately the same size as the state of Rhode Island. Because of its immense scale, it is a vital subject for scientific study. Most of the glacier is located within the Wrangell-St. Elias National Park and Preserve.

To understand how this glacier works, one must look at its three main parts. The Malaspina is actually a convergence of three distinct glaciers. These are the Seward Glacier, the Agassiz Glacier, and the Marvine/Hayden Glacier. They all flow out from the Saint Elias Mountains. They meet on the coastal plain facing the Gulf of Alaska.

The Seward Glacier is the largest and forms the primary piedmont lobe. The Agassiz Glacier contributes a secondary lobe to the west. The Marvine/Hayden Glacier is the smallest and forms the easternmost lobe. While they are often called one glacier, they are officially classified as independent entities.

Geography defines how these ice flows interact with the land and water. The glaciers fill the coastal plain between Icy Bay and Yakutat Bay. However, they do not actually reach the ocean water. This means they are not classified as tidewater glaciers. They also do not end inside the lakes found on their margins. For example, the Seward and Marvine/Hayden glaciers terminate near Malaspina Lake. Because they do not end in the water, they are not lacustrine glaciers either. The ice is incredibly deep in certain areas. In some places, the glacier is up to 2,600 feet thick. Its bottom can even reach elevations as much as 2,600 feet below sea level.

Two specific lakes sit along the edges of this massive ice system. Oily Lake is located to the northwest. It sits at the foot of the Samovar Hills between the Agassiz and Seward glaciers. Malaspina Lake is located to the southeast near Yakutat Bay. These lakes mark the boundaries where the ice meets the surrounding terrain. The presence of these lakes and hills helps define the shape of the glacier lobes. The massive scale of the ice creates a unique environment for these water bodies.

The history of the glacier's naming reflects the exploration of the region. The Tlingit people have a name for it that translates to "big glacier." The colonial name honors Alessandro Malaspina. He was a Tuscan explorer who served in the Spanish Navy. He visited this specific region in 1791. Later, in 1874, W. H. Dall of the United States Coast Survey gave it a different name. He called it the Malaspina Plateau. He did so because he did not realize its true geological character at the time. In October 1969, the site became a National Natural Landmark.

Modern science allows us to track how this giant ice mass changes over time. Scientists use radar data and aerial photographs to monitor the glacier. Data dating back to 1972 provides a clear record of its movement and size. This research shows that the Malaspina-Seward glacier system has lost significant thickness. Between 1980 and 2000, the system lost about 15 feet of thickness.

Even though 15 feet may seem small for such a giant, it is very significant. Because the glacier is so large, this shrinkage had a global impact. This melting contributed 0.5% to the rise in global sea levels.

The Malaspina Glacier connects many different scientific ideas. It serves as a primary example of how mountain glaciers transition into piedmont glaciers. It also shows how individual ice flows can merge into a single massive system. By studying its thickness and its relationship to the sea, scientists learn about the Earth's climate. The way the ice responds to temperature changes helps us understand global patterns. It is a massive, moving piece of the Earth's physical system.