Episodic reactivation of large‐scale push moraines in front of the advancing Taku Glacier, Alaska

Kuriger, E. M.; Truffer, Martin; Motyka, R. J.; Bucki, A. K.

doi:10.1029/2005jf000385

Cited by 24 publications

(44 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These studies indicate the importance of tidewater glacier dynamics on Taku Glacier's present behavior (Motyka and Begét, 1996;Motyka et al, 2002;Motyka and Echelmeyer, 2003;Kuriger et al, 2006;Motkya et al, 2006;Pelto et al, 2008) and are discussed in detail below.…”

Section: Previous Workmentioning

confidence: 95%

The Response of Taku and Lemon Creek Glaciers to Climate

Criscitiello¹,

Kelly

Tremblay

2010

Arctic, Antarctic, and Alpine Research

View full text Add to dashboard Cite

Section: Previous Workmentioning

confidence: 95%

The Response of Taku and Lemon Creek Glaciers to Climate

Criscitiello¹,

Kelly

Tremblay

2010

Arctic, Antarctic, and Alpine Research

View full text Add to dashboard Cite

“…Examination of the internal structure of terminal moraines has historically been achieved using direct observations of structure and sedimentology (Van der Wateren, 1995;Phillips et al, 2002;Benediktsson et al, 2009) and non-invasive geophysical methods such as GPR (Bakker, 2004;Kuriger et al, 2005). In this study, we employ a range of different field and remote techniques.…”

Section: Methodsmentioning

confidence: 99%

A polyphase glacitectonic model for ice-marginal retreat and terminal moraine development: the Middle Pleistocene British Ice Sheet, northern Norfolk, UK

Lee

Phillips

Booth

et al. 2013

Proceedings of the Geologists' Association

View full text Add to dashboard Cite

Recent investigations from modern environments demonstrate that many terminal moraines do not simply record a single glacial maximum, but instead reveal a complex pattern of ice-marginal behaviour including polyphase retreat. Within this study, we examine the geomorphology, geology and internal structure of a terminal moraine complex -the 'Cromer Ridge' in north Norfolk to reconstruct patterns of ice-marginal behaviour. Previously, this landform was interpreted as the limit of a southern extension of the British Ice Sheet during a Middle Pleistocene glaciation. Evidence presented here reveals a more complicated pattern of ice-marginal behaviour with the 'Cromer Ridge' reinterpreted as a 'complex' comprising several ridge elements. We propose that the maximum ice extent lay further to the south, with the size and morphology of the largest ridge element (the 'Cromer Ridge' as previously defined) a facet of thrust-stacking at an ice-marginal stillstand. We recognise multiple oscillations of the ice-front recorded against a twelve-stage model for the decay of the southern margins of a fast-flowing lobe of North Sea ice. Changes in ice-marginal dynamics are identified by the superimposition and lateral and vertical evolution of glacitectonic styles. Differences between these various states, and switches between 'shallow' and 'deep' thinskinned glacitectonics, are strongly influenced by sub-marginal and proglacial water availability. Examination of the evidence for the morphostratigraphic proposals for the glacitectonic assemblage, within the context of the above interpretation, suggests that many of the 'glacigenic landforms' are erosional and a MIS 12 age of formation is favored although several anomalies remain to be explained. IntroductionTerminal moraines are an important landform within the glacial landsystem and are widely recognised within both contemporary (Boulton et al., 1996(Boulton et al., , 1999Bennett, 2001; Evans and Twigg, 2002; Evans, 2005;Benediktsson et al., 2010) and relict glacial environments (van der Meer, 1987; Lee, J.R., Phillips, E., Booth, S.J., Rose, J., Jordan, H.M., Pawley, S.M., Warren, M., Lawley, R.S. 2013. A polyphase glacitectonic model for ice-marginal retreat and terminal moraine development: the Middle Pleistocene British Ice Sheet, northern Norfolk, UK. Proceedings of the Geologists' Association, 124, 753-777. PRE-PROOF ACCEPTEF MANUSCRIPT.2 Hart, 1990;Van der Wateren, 1995;Harris et al., 1997;Phillips et al., 2002;Wilson, 2002;Thomas and Chiverrell, 2007;Johnson et al., 2013). Previously, they have been considered as providing a visible record of a maximum extent of glacier advance, although many now consider them to provide a more dynamic record of glacier retreat (e.g. Thomas, 1984;Thomas et al., 2004;Thomas and Chiverrell, 2007;Lüthgens and Böse, 2011; Clark et al., 2012).The formation of terminal moraines typically involves the complex interplay between ice-marginal to sub-marginal sedimentation and glacitectonics; the latter including proglacial and sub-margina...

show abstract

“…This uncertainty reflects the ability of the advancing terminus to override or entrench itself in proglacial sediments (e.g., Kuriger et al, 2006;Motyka et al, 2006). Because deposition and erosion can both modify the elevation of the glacier bed, we do not make any assumptions as to whether the glacier bed has shallowed or deepened over time.…”

Section: Bathymetrymentioning

confidence: 99%

Dynamic Changes at Yahtse Glacier, the Most Rapidly Advancing Tidewater Glacier in Alaska

et al. 2017

View full text Add to dashboard Cite

Since 1990, Yahtse Glacier in southern Alaska has advanced at an average rate of ∼100 m year −1 despite a negative mass balance, widespread thinning in its accumulation area, and a low accumulation-area ratio. To better understand the interannual and seasonal changes at Yahtse and the processes driving these changes, we construct velocity and ice surface elevation time series spanning the years 1985-2016 and 2000-2014, respectively, using satellite optical and synthetic aperture radar (SAR) observations. We find contrasting seasonal dynamics above and below a steep (up to 35% slope) icefall located approximately 6 km from the terminus. Above the icefall, velocities peak in May and reach their minima in October synchronous with the development of a small embayment at the calving terminus. The up-glacier minimum speeds, embayment, and plume of turbid water that emerges from the embayment are consistent with an efficient, channelized subglacial drainage system that lowers basal water pressures and leads to focused submarine melt in the calving embayment. However, velocities near the terminus are fastest in the winter, following terminus retreat, possibly off of a terminal moraine that results in decreased backstress. Between 1996 and 2016 the terminus decelerated by ∼40% at an average rate of ∼0.4 m day −1 year −1 , transitioned from tensile to compressive longitudinal strain rates, and dynamically thickened at rates of 1-6 m year −1 , which we hypothesize is in response to the development and advance of a terminal moraine. The described interannual changes decay significantly upstream of the icefall, indicating that the icefall may inhibit the upstream transmission of stress perturbations. We suggest that diminished stress transmission across the icefall could allow moraine-enabled terminus advance despite mass loss in Yahtse's upper basin. Our work highlights the importance of glacier geometry in controlling tidewater glacier re-advance, particularly in a climate favoring increasing equilibrium line altitudes.

show abstract

Episodic reactivation of large‐scale push moraines in front of the advancing Taku Glacier, Alaska

Cited by 24 publications

References 33 publications

The Response of Taku and Lemon Creek Glaciers to Climate

The Response of Taku and Lemon Creek Glaciers to Climate

A polyphase glacitectonic model for ice-marginal retreat and terminal moraine development: the Middle Pleistocene British Ice Sheet, northern Norfolk, UK

Dynamic Changes at Yahtse Glacier, the Most Rapidly Advancing Tidewater Glacier in Alaska

Contact Info

Product

Resources

About