Exploration and estimation of gravel resource potential in southeast Chukchi Sea continental shelf off Kivalina, Alaska

Abstract

Frequent storm surges in the Alaskan arctic result in washovers and high erosion of barrier islands. The village council of Kivalina has resolved to relocate from its present location on a barrier island in Northwest arctic Alaska to an adjacent onshore site. The relocation plan envisages excavation of upper 4 meter of the 25 km² onshore permafrost ground and construction of a foundation pad. The objective of this research is to estimate the gravel resource potential in the continental shelf off Kivalina. In this context seismic surveys and sediment sampling were conducted. The seismic surveys were of limited use as they failed to resolve the upper 1-2 m of the seafloor. The lithostratigraphy indicated dominance of the 2.4-3.4 mm size fraction in the region north of Kivalina. The geostatistical analysis indicated an omnidirectional variogram fit to the data with ordinary kriging producing the best kriging estimate of the gravel resource potential. At least 20 x 10⁶ m³ of gravel above the 90 % cut-off is present in the upper 0.5 m of the seafloor. The regional Pleistocene glaciation has affected the lateral variations in gravel abundance in the nearshore southeast Chukchi Sea.