Bear Glacier EarthCache

Bear Glacier is located in Alaska's Kenai Fjords National Park. The glacier's immense ice walls and blue colors create a breathtaking sight, attracting visitors from all over the world. From the posted coordinates, you'll be in Resurrection Bay, which is a picturesque inlet located on the Kenai Peninsula in Alaska. It's known for its stunning natural beauty, surrounded by rugged mountains and lush forests. The bay serves as the gateway to Kenai Fjords National Park. Visitors to Resurrection Bay can enjoy boat tours, wildlife viewing, and various outdoor activities, immersing themselves in the unspoiled wilderness of Alaska's coastal region.

If you look towards the Bear glacier, you'll notice its terminal moraine. Terminal moraines are significant geological features created by glaciers. At the Bear Glacier in Alaska, the terminal moraine marks the furthest point of the glacier's advance before it started retreating. As the glacier moves forward, it carries rocks, debris, and sediment from the mountains and valleys it erodes. When the glacier melts or recedes, this material gets deposited in a distinct ridge-like formation, forming the terminal moraine. The terminal moraine at Bear Glacier serves as a visible record of the glacier's past extent, helping geologists understand the glacier's historical behavior and retreat patterns. By analyzing the composition and characteristics of the moraine's sediments, scientists can gain insights into the glacier's erosive capabilities, the climate conditions during its formation, and changes in its size over time.

While not entirely visible from the water, another feature worth mentioning is the proglacial lagoon. Proglacial lagoons are geological features formed near the terminus of a retreating glacier. In the case of Bear Glacier, Alaska, as the glacier slowly recedes, it leaves behind a depression in the landscape, which becomes filled with meltwater and runoff from the ice. This water accumulates in the proglacial lagoon, creating a unique and dynamic environment. The lagoon at Bear Glacier serves as a vital part of the glacial ecosystem, providing habitat for various aquatic organisms. The sediments carried by the glacier get deposited in the lagoon, shaping its geomorphology and influencing its water chemistry. The flooding of the proglacial lagoon at Bear Glacier can occur as the glacier continues to melt and retreat. As the glacier's ice melts, large volumes of meltwater are released, leading to an increase in water levels within the lagoon. The inflow of additional water from snowmelt and rainfall can further contribute to lagoon flooding. During periods of intense melting or heavy precipitation, the lagoon's water level may rise significantly, breaching its natural boundaries and potentially flooding surrounding low-lying areas. This flooding phenomenon can lead to changes in the lagoon's shape and size, impacting the distribution of sediments and altering the overall geomorphology of the area.

1. Describe the terminal moraine. How long is it? How tall is it? Is it covered in vegetation or just exposed glacial till? Is the height of the terminal moraine consistent, or does it vary?
2. As of July 2023, Bear Glacier Lagoon last burst in September, 20222. Do you see any evidence of this burst on the terminal moraine, or along the shoreline?
3. How do you think the terminal moraine influenced the formation of the proglacial lagoon?
4. Upload a photo with the Bear Glacier or Resurrection Bay. You don't have to be in the photo, though it is strongly encouraged.