Denali National Park Alaska By John Abraham

Relief Map of Denali National Park

Contour Map of Denali National Park

Location of Denali National Park

Important land features of Denali national park Mount Mc Kinley Mount Mc Kinley is the tallest mountain in north America. Glaciers Glaciers go through Denali leaving scratch marks behind. Bodies of water Bodies of water are all over Denali in the summer.

When did Denali National Park Become A National Park? In , a naturalist named Charles Sheldon saw that mining and big game hunters were coming to the Denali area. He knew the increase in visitors would not be good for the natural environment and wildlife. He returned to Washington, DC and proposed that it become a National Park to protect the wildlife. He was successful and President Wilson signed a bill into law to make Denali a National Park on February 26, 1917.

Environmental Issues Facing Denali National Park Human Development – Alters the natural landscape and brings more humans to places they wouldn’t normally have gone Global Warming – Increased global temperatures have caused the glaciers to thin and melt away. Air Quality – Pollution from Asia and Europe makes its way to Denali. Exotic Plants – Plants that aren’t native to the park are introduced and are invasive. They climb and spread over native plants. An example is bird vetch, an invasive plant. Sound Quality – Human generated noise disturbs the sounds of nature. Earthquakes – Because of plate tectonics and Denali’s location on the active Denali fault, strong earthquakes are possible in the park. Earthquakes can damage natural features and human developments. Denali continues to grow by approximately 1mm per year. Migratory Birds – Migration patterns are in danger because of human development and activity in the park.

Special Features and Landforms in Denali National Park Denali Denali is the tallest mountain peak in North America at 20,320 feet (3 rd highest peak in the world) Denali means “The Great One” or “The Tall One” in Athabascan (Native American) Was previously named Mount McKinley after President McKinley in 1896 In 2015 it was given its original name back of Denali Primarily consists of granite stone, which is a very hard stone, so it resists weathering and erosion Mountain Range Denali is part of the Alaska Range of mountains Except for Denali the Alaska Range is consists of limestone, sandstone and shale. These rocks are softer and have weathered. This creates a big difference in the heights of Denali and the rest of the Alaska range.

Special Features and Landforms in Denali National Park (continued) Glaciers Glaciers are large bodies of ice that slowly move down mountains and over land and water. They are formed when snow gathers faster than it melts. In Denali glaciers cover approximately 1/6 of the park Glaciers go through Denali leaving scratch marks behind. Bodies of water Bodies of water are all over Denali in the summer. Many rivers, lakes and streams that are fed by glacier water Not good fishing areas because of glacier silt

Technologies Used in Denali National Park Seismographs – used to study earthquakes in the park and along the Alaska Range. Cameras and motion detectors are being used to observe bear behavior. Air quality Monitors – used to study levels of pollutants in the park. Telmetry put collars on wildlife that send radio signals to tell people where it is. Aerial Surveys They use helicopters and other flying vehicles to take surveys. Weather stations – located throughout the park and help provide current information for visitors as well as data for studying climate change. GPS Is used to determine were certain things are. Internet – Used to inform visitors about the park and share information. (Denali visibility webcam)

Rocks in Denali National Park Denali is one of the few mountains in the world that is made up almost of all one type of rock. In this case, Denali is made of the igneous rock, granite. Denali’s neighboring mountains in the Alaska Range are made up of sedimentary rocks. These are primarily limestone, sandstone and shale. These rocks are much weaker than granite and therefore erode faster than Denali. Granite From left to right: sandstone, shale, and limestone

How was Denali National Park Formed? The oldest rocks in the park date back to the Paleozoic era, about million years ago The park is located on the Denali fault, an active fault where the Pacific Plate is sliding underneath the North American Plate. As this subduction happened during the last 100 million years, the mountain ranges we see today in Southern Alaska were formed. This includes coastal mountain ranges and inland ranges such as the Alaska Range that includes Denali. Denali formed about 70 million years ago when a huge pool of magma several kilometers beneath the surface cooled very slowly and formed the hard igneous rock, granite. Then, because of it’s location on the fault, it has been pushed up over millions of years. Denali’s neighboring mountains consist of soft rocks (limestone, shale) that weather easily, compared to the Denali’s granite. This creates a big difference in the heights of Denali and the rest of the Alaska Range.

How is the Land inside the park currently changing? Changes due to Plate Tectonics The forces of plate tectonics that created the park continue to impact the park today. The Pacific Plate continues to actively subduct under the North American Plate at a rate of 2 inches per year. These subduction forces result in the mountains continuing to “grow”. The mountains surrounding Denali grow and weather at about the same rate. Since Denali does not weather nearly as much as its neighboring mountains, it actually continues to grow at a rate of 1 mm per year. Earthquake activity along the Denali fault continues to impact the park’s landscape. In 2002, the Denali fault experienced a Magnitude 7.9 earthquake. This resulted in cracks in the ground up to 6.7 m (22 feet wide) and mudslides that move huge volumes of earth.

How is the Land inside the park currently changing? (continued) Changes due to Global Warming Nearly all glaciers surveyed in Alaska are melting due to increased global temperatures. Thinning rates in the last 5 to 7 years are more than twice those seen in previous years. Half of the water flowing into the oceans, globally, due to melting glaciers, is a result of melting in Alaska. The increased temperatures are causing the park’s permafrost regions (areas frozen for more than 2 years) to thaw. This allows new vegetation to grow, filling in glacial wash areas and shrinking pond/lake areas. Changes due to Human Development One final area is the impact that man is having on the park. As more people visit the park, additional facilities are constructed which alters the landscape. In addition where these visitors go can destroy the delicate tundra vegetation. Sunset Glacier, Denali National Park. Above photo shows the decrease in glacial ice that has occurred over 70 years. It is important to remember this glacial ice is hundreds of feet thick.

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Types of Rocks in Denali Technologies Used in Denali Bibliography (continued)

How was the Park formed? page?sort=map&sortb=5&id=Mt_Eielson_Thoro_01 How is the Land inside the park currently changing? page?sort=map&sortb=5&id=Mt_Eielson_Thoro_01 Bibliography (continued)