Time-dependent uplift of the Kenai Peninsula and adjacent regions of south central Alaska since the 1964 Prince William Sound earthquake

1996 ◽  
Vol 101 (B4) ◽  
pp. 8595-8604 ◽  
Author(s):  
Steven C. Cohen
Keyword(s):  
Time Dependent ◽  
Prince William Sound ◽  
Kenai Peninsula ◽  
South Central

scholarly journals Holocene biogeography of Tsuga mertensiana and other conifers in the Kenai Mountains and Prince William Sound, south-central Alaska

The Holocene ◽  
2016 ◽  
Vol 27 (4) ◽  
pp. 485-495 ◽  
Author(s):  
R Scott Anderson ◽  
Darrell S Kaufman ◽  
Edward Berg ◽  
Caleb Schiff ◽  
Thomas Daigle
Keyword(s):  
Climatic Factors ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Early Holocene ◽  
Ice Age ◽  
Prince William Sound ◽  
Conifer Forest ◽  
The Holocene ◽  
South Central ◽  
Tsuga Mertensiana

Several important North American coastal conifers – having immigrated during the Holocene from the southeast – reach their northern and upper elevation limits in south-central Alaska. However, our understanding of the specific timing of migration has been incomplete. Here, we use two new pollen profiles from a coastal and a high-elevation site in the Eastern Kenai Peninsula–Prince William Sound region, along with other published pollen records, to investigate the Holocene biogeography and development history of the modern coastal Picea (spruce)– Tsuga (hemlock) forest. Tsuga mertensiana became established at Mica Lake (100 m elevation, near Prince William Sound) by 6000 cal. BP and at Goat Lake (550 m elevation in the Kenai Mountains) sometime after 3000 years ago. Tsuga heterophylla was the last major conifer to arrive in the region. Although driven partially by climate change, major vegetation changes during much of the Holocene are difficult to interpret exclusively in terms of climate, with periods of slow migration alternating with more rapid movement. T. mertensiana expanded slowly northeastward in the early Holocene, compared with Picea sitchensis or T. heterophylla. Difficulty of invading an already established conifer forest may account for this. We suggest that during the early Holocene, non-climatic factors as well as proximity to refugia, influenced rates of migration. Climate may have been more important after ~2600 cal. BP. Continued expansion of T. mertensiana at Goat Lake at the Medieval Climate Anomaly (MCA)–‘Little Ice Age’ (‘LIA’) transition suggests warm and wet winters. But expansion of T. mertensiana at both sites was arrested during the colder climate of the ‘LIA’. The decline was more extensive at Goat Lake, where climatic conditions may have been severe enough to reduce or eliminate the T. mertensiana population. T. mertensiana continued its expansion around Goat Lake after the ‘LIA’.

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.

scholarly journals Comprhensive Approach to the Analysis of the 3D Kinematics Deformation with appliction to the Kenai Peninsula

2011 ◽  
Vol 1 (1) ◽  
pp. 59-73 ◽  
Author(s):  
M. Hossainali ◽  
M. Becker ◽  
E. Groten
Keyword(s):  
Surface Deformation ◽  
Regularization Parameter ◽  
Vertical Direction ◽  
Three Dimensions ◽  
Deformation Tensor ◽  
Deformation Analysis ◽  
Kenai Peninsula ◽  
3D Kinematics ◽  
South Central ◽  
Lagrangian Formulations

Comprhensive Approach to the Analysis of the 3D Kinematics Deformation with appliction to the Kenai PeninsulaThe problem of analyzing surface deformation of the Earth's crust in three-dimensions is discussed. The isoparametric and Lagrangian formulations of deformation are extended from 2D to 3D. Analytical and numerical investigation of problem conditioning proves that analyzing the 3D kinematics of deformation can be an ill-posed problem. The required mathematical elements for solving this problem, including sensitivity analysis of the deformation tensor and regularization, are proposed. Regularized deformation tensors were computed using the method of truncated singular value decomposition (TSVD). The optimal regularization parameter was attained by minimizing regularization errors. Regularization errors were assessed using the corresponding 2D results of deformation analysis. The proposed methods were applied to the GPS network in the Kenai Peninsula, south-central Alaska, in order to compute the 3D pattern of postseismic crustal deformation in this area. Computed deformation in the vertical direction is compared to the existing pattern of vertical deformation obtained from the combination of precise leveling, gravity and GPS measurements from other studies on this area.

scholarly journals Long-term associations and insights on social structure of the Humpback whales in Prince William Sound, Alaska

2020 ◽  
Author(s):  
Olga von Ziegesar ◽  
Shelley Gill ◽  
Beth Goodwin
Keyword(s):  
Social Structure ◽  
Feeding Habits ◽  
North Pacific Ocean ◽  
Small Population ◽  
Population Characteristics ◽  
Humpback Whales ◽  
Prince William Sound ◽  
The North ◽  
South Central

AbstractHumpback whale (Megaptera novaeangliae) social structure is more complex than previously thought. Because of the fluid “fission-fusion” nature of their relationships: individuals foraging, traveling, and socializing with a number of animals, where associations form and are broken numerous times, little has been confirmed about their long-term associations. Humpback whales of the North Pacific Ocean migrate annually between tropical breeding areas to northern latitudes where they congregate and feed. The purpose of this study was to explore the social and feeding habits of the summer population of humpback whales returning to Prince William Sound (PWS) in the south central coast of Alaska. Fluke photographs of pigmentation patterns were used to document individual whales between the years 1983 and 2009 to determine, population characteristics, reproductive rates, long-term associations, feeding habits and spatial partitioning. During the 27 year study period there were 3,017 encounters with 405 unique whales. Forty of these whales (9.88%) had long sighting histories, showing strong site fidelity. Association indices for all pairs of whales were calculated. Long-lasting associations were found between thirty-two of the forty whales. Two distinct groups were determined by the highest association coefficients. Although the overall ranges of the two groups overlapped, they did not often mingle and offspring did not join their maternal group. All but two females had enduring bonds with at least one male. Associate males were sometimes found at a distance from others of their “clan” and would rejoin periodically. Two whales from one of these clans were found together in Hawaiian waters, a male escorting a female with a newborn calf, suggesting these long lasting associations endure through migration and into the southern breeding areas. Optimal observation conditions of a small population of humpback whales in sheltered waters allowed the discovery of two social groups enduring almost three decades.

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