Fish Creek flows generally northeast for approximately 110 miles (177 km) to Harrison Bay at the western edge of the Colville River Delta, about 141 miles (230 km) southeast of Utqiaġvik and 12 miles (19 km) north-northwest of Nuiqsut, Alaska. The creek drains an area of about 1.1 million acres (460,000 ha) entirely within the zone of continuous permafrost in the Arctic Coastal Plain. The local name “Fish Creek” was first reported in 1951 by the US Coast and Geodetic Survey. Harrison Bay spans about 57 miles (92 km) across, situated on the Beaufort Sea coast between Cape Halkett to the west and Oliktok Point to the east. On July 26, 1837, Peter W. Dease and Thomas Simpson named the bay after Benjamin Harrison, then deputy governor of the Hudson’s Bay Company. In 1923, President Warren G. Harding established the Naval Petroleum Reserve Number 4, as the United States was converting its Navy to oil from coal. The name was changed to the National Petroleum Reserve-Alaska in 1976, and in 1980, management authority for oil and gas leasing was transferred to the Bureau of Land Management in the US Department of the Interior. The oil-bearing sediments of the reserve are primarily found in sandstone bedrock. In the Fish Creek delta area, this is part of the Sagavanirktok Formation, which consists of siltstone, shale, and sandstone, with a maximum thickness of less than 525 feet (160 m). This bedrock is buried by extensive silt and sand deltas, with thick accumulations of frozen peat formed at the mouths of the Colville River and Fish Creek since sea levels reached their current elevation during the middle to late Holocene epoch. Permafrost is soil, rock, or sediment that has remained continuously frozen for over two years. In areas not covered by ice, it lies beneath a layer of vegetation, peat, and soil that freezes and thaws annually. Winter temperatures cause the soil to contract, creating cracks in the permafrost. In spring and summer, melting snow and ice fill these cracks, which then freeze to form ice wedges. The mean annual air temperature required to form ice wedges is −6°C to −8°C or colder. Since water expands when it freezes, the crack enlarges with each freeze-thaw cycle, eventually pushing the material above into ridges, forming geometric shapes on the tundra.

The Iñupiat people of Utqiaġvik and Nuiqsut rely heavily on subsistence hunting and fishing. Depending on their location, they harvest walruses, seals, whales, polar bears, caribou, and fish. Along with other Inuit groups, the Iñupiat originate from the Thule people, who migrated from islands in the Bering Sea around 300 BC. Their traditional territory includes lands north from Norton Sound on the Bering Sea to the Arctic Coastal Plain and east to the Mackenzie River. Historically, there were many small settlements along the coast used by family groups as seasonal whaling and fishing camps. In 1837, Dease and Simpson became the first Europeans to explore this part of the Beaufort Sea coast when the Hudson’s Bay Company reached an agreement with the British Admiralty to survey and map the north coast. They sailed down the Mackenzie River in Canada and then westward past the Colville River Delta, reaching a point beyond Cape Simpson. From there, they proceeded west on foot to Point Barrow. Additional knowledge of the coast was gained from expeditions sent between 1848 and 1853 to search for the missing party of Sir John Franklin. In 1849, Lieutenant William Pullen sailed a small boat from Kotzebue Sound around the Arctic coast to the Mackenzie River. Starting in the early 1900s, the US Geological Survey sponsored expeditions for exploring and investigating the Arctic coast. Notable participants included William J. Peters and Frank C. Schraeder in 1901, and Ernest K. Leffingwell and Rudolph M. Anderson from 1906 to 1914. Vilhjalmur Stefansson made further contributions between 1908 and 1918. With the establishment of the Naval Petroleum Reserve in 1923, further investigations by the US Geological Survey were requested by the Navy. By the late 1940s, field surveys provided a reasonably complete, if generalized, picture of the major geological features of the reserve and surrounding areas. Since the 1970s, oil and mineral resources have become significant revenue sources for the Iñupiat villages of the Arctic Coastal Plain. However, these developments have also posed challenges to their culture and lifestyle, exacerbated by climate change. 

The coastal tundra is increasingly inundated by rising sea levels. The Arctic Coastal Plain’s flat topography means even small sea-level changes can flood vast low-lying areas. In 1970, a storm surge of 10 feet (3 m) reached 3 miles (5 km) inland, as evidenced by wood lines and salt-burned tundra. Rising atmospheric and oceanic temperatures are accelerating coastal erosion by reducing sea ice duration, increasing storm surge magnitude, and raising permafrost temperatures. Storm surges over an ice-free Beaufort Sea drive coastal erosion and flood inland, salinizing lakes and affecting tundra habitats. Salt-burned tundra, indicated by varying necrosis levels, can result from these surges. However, the specific vegetation types susceptible to storm surges and the duration of these effects remain uncertain. Coastal erosion and storm surge flooding interact with changes in the terrestrial permafrost environment, such as progressive lake expansion due to thermokarst erosion and potential land level lowering due to subsidence or deflation of ice-rich permafrost. The ridges surrounding tundra polygons at Fish Creek facilitate water ponding, exacerbating thawing and subsidence and leading to more frequent ocean flooding. Thermokarst refers to the processes, landforms, and sediments associated with the loss of ice in permafrost due to thawing. Thawing permafrost reduces soil strength as it transitions from a frozen to an unfrozen state and decreases soil volume due to ice loss, resulting in ground subsidence. The degree of subsidence depends on the thickness of the thawed soil and is most noticeable above intersecting ice wedges. The ice-rich soils and low relief of the Arctic Coastal Plain make vegetation highly sensitive to permafrost thaw-induced subsidence. Saltwater inundation can kill typical tundra vegetation, and repeated inundation increases thermal conductivity, potentially triggering further permafrost thaw and subsidence. Read more here and here. Explore more of the tundra polygons at the mouth of Fish Creek and Harrison Bay here: