A Comprehensive Study of the Seismicity of the Kenai Peninsula-Cook Inlet Region, South-Central Alaska

2009 ◽  
Vol 99 (4) ◽  
pp. 2208-2222 ◽  
Author(s):  
D. I. Doser ◽  
A. M. Veilleux
Keyword(s):  
Cook Inlet ◽  
Kenai Peninsula ◽  
South Central ◽  
Inlet Region ◽  
Comprehensive Study

The Hayes Tephra Deposits, and Upper Holocene Marker Horizon in South-Central Alaska

1990 ◽  
Vol 33 (3) ◽  
pp. 276-290 ◽  
Author(s):  
James R. Riehle ◽  
Peter M. Bowers ◽  
Thomas A. Ager
Keyword(s):  
Cook Inlet ◽  
Radiocarbon Dates ◽  
Fine Grained ◽  
South Central ◽  
Inlet Region ◽  
Tephra Deposits ◽  
Phenocryst Content

AbstractThe most widespread of all Holocene tephra deposits in the Cook Inlet region of south-central Alaska is a set of deposits from Hayes volcano. Because of their unique phenocryst content—biotite in rare amounts and a high proportion of amphibole to pyroxene—the deposits are readily identifiable at all but the most distant sites where they are very fine grained. Eighteen radiocarbon dates from eight upland sites limit the age of the tephra set to between about 3500 and 3800 yr. The set originated at Hayes volcano in the Tordrillo Mountains 150 km northwest of Anchorage; seven or possibly eight closely succeeding deposits, low-silica dacite in composition, compose two main lobes that extend northeast for 400 km and south for at least 250 km from the vent. We estimate the total tephra volume to be 10 km3; multiple layers imply four to six larger and two or three smaller eruptions. The deposits are a nearly isochronous marker horizon that should be useful in future archeologic, geologic, and palynologic studies in the region.

scholarly journals Assessment of undiscovered oil and gas resources of the Cook Inlet region, south-central Alaska, 2011

Fact Sheet ◽  
2011 ◽  
Author(s):  
Richard G. Stanley ◽  
Ronald R. Charpentier ◽  
Troy A. Cook ◽  
David W. Houseknecht ◽  
Timothy R. Klett ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Cook Inlet ◽  
South Central ◽  
Inlet Region ◽  
Oil And Gas Resources

Impact of a Larger Fore‐Arc Region on Earthquake Ground Motions in South‐Central Alaska Including the 2018 M 7.1 Anchorage Inslab Earthquake

2019 ◽  
Vol 91 (1) ◽  
pp. 174-182 ◽  
Author(s):  
Chris H. Cramer ◽  
Eric Jambo
Keyword(s):  
Subduction Zones ◽  
Thermal State ◽  
Ground Motions ◽  
Historical Earthquakes ◽  
Cook Inlet ◽  
Damage Potential ◽  
Motion Models ◽  
South Central ◽  
Inlet Region ◽  
Subducting Plate

Abstract The thermal state of the crust and mantle in subduction zones is controlled by the depth of the subducting plate. With low‐angle subduction, like at the eastern end of the Alaska subduction zone, the less attenuating fore‐arc is extended farther from the trench and can effect ground motions in addition to source and site effects. Recent crustal and subduction earthquakes in south‐central Alaska, including the 2018 M 7.1 Anchorage event, demonstrate these effects. Inslab earthquake waves in the subducting plate can propagate up the slab to the fore‐arc region with less attenuation, causing an increase in observed ground motions. Long‐period ground motions from the 2018 M 7.1 Anchorage earthquake are significantly higher than predicted ground motions from current subduction ground‐motion models within 50–100 km of the epicenter. At short periods, ground motions show reduced amplitudes due to nonlinear sediment effects in the Anchorage area, reducing the damage potential of the earthquake. At long periods, ground motions are little affected by sediment nonlinearity and remain higher than expected. The duration of shaking was too short for widespread liquefaction effects, unlike during the 1964 M 9.2 earthquake. Other historical earthquakes have produced similar increases in ground motions in the Cook Inlet and Kenai Peninsula region. At both short and long periods, ground motions from the 2016 Iniskin M 7.1 inslab earthquake are higher than expected in the Cook Inlet region. The 2015 Redoubt M 6.3 inslab earthquake also shows increased ground motions in the Cook Inlet region at all periods. Crustal Q estimates from Lg waves show less attenuation in south‐central Alaska at longer periods. In the larger south‐central Alaska region crustal Q(f)=336f0.34 compared to Q(f)=217f0.84 for all of Alaska with most of the decrease in attenuation at frequencies below 2 Hz.

scholarly journals U.S. Geological Survey 2011 assessment of undiscovered oil and gas resources of the Cook Inlet region, south-central Alaska

2011 ◽  
Author(s):  
Richard G. Stanley ◽  
Brenda S. Pierce ◽  
David W. Houseknecht
Keyword(s):  
Oil And Gas ◽  
Geological Survey ◽  
Cook Inlet ◽  
South Central ◽  
Inlet Region ◽  
Oil And Gas Resources

Volcanoes of the Wrangell Mountains and Cook Inlet region, Alaska: selected photographs

Data Series ◽  
10.3133/ds39 ◽  
2001 ◽  
Author(s):  
Christina A. Neal ◽  
Robert G. McGimsey ◽  
Michael F. Diggles
Keyword(s):  
Cook Inlet ◽  
Inlet Region

Pumice deposits in the Alaska Peninsula-Cook Inlet region

1952 ◽  
Author(s):  
R.M. Moxham
Keyword(s):  
Cook Inlet ◽  
Alaska Peninsula ◽  
Inlet Region

Comment on “Wetland drying and succession across the Kenai Peninsula Lowlands, south-central Alaska”Appears in Can. J. For. Res. 35: 1931-1941 (2005).

2011 ◽  
Vol 41 (2) ◽  
pp. 425-428 ◽  
Author(s):  
Michael B. Gracz
Keyword(s):  
Climate Change ◽  
Sensitivity Analysis ◽  
Forest Succession ◽  
Aerial Photographs ◽  
Lake Levels ◽  
Kenai Peninsula ◽  
Wetland Ecosystems ◽  
South Central ◽  
Tectonic Processes

Klein et al. (2005, Can. J. For. Res. 35: 1931–1941) compare aerial photographs and report dramatically lower lake levels on the northern Kenai Peninsula, Alaska. They hypothesize that the lower lake levels may be caused by a decline in moisture surplus driven by climate change. However, the reported decline in surplus appears to be insufficient to explain the lower lake levels. Here I develop a simple sensitivity analysis to test their hypothesis and also show how tectonic processes such as the Great Alaskan earthquake could dramatically lower lake levels by fracturing an underlying aquitard. Tectonic processes, therefore, could potentially alter forest succession and wetland ecosystems by inducing hydrologic changes that mimic changes in climate.

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