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Overseas, relict deep-seated coastal landslides have attracted significant analysis because of potential hazards caused by sea level rise and climate change. Despite the rapid growth in the Auckland region, regional coastal landslide hazards are poorly understood. We investigated the geomorphology and material properties of Ohuka coastal landslide on the southwestern coastline of the Auckland region, to better understand the failure mechanism. The site is formed on weak Neogene sediments of varying lithological properties, with very low angles of dip, exposed on both the seaward (west) and landward (east) flanks of Ohuka Hill. Displacement appears to have been rotational, along a low-angled basal shear surface, the Koheroa Clay Seam. The surface geomorphology consists of discontinuous uphill-facing scarplets indictive of rotational slump blocks, along the basal shear surface. However, the preservation of slump block surface topography is hindered due to the lack of a thick, strong caprock, and high annual rainfall (1400 mm), and erosion. The proposed failure mechanism and general geometry is consistent with correlations between graben width and depth to failure plane reported from bedding-controlled coastal landslides formed on low dip angles in southern England. This provides important context, given the paucity of New Zealand bedding-controlled coastal landslide case studies. [ABSTRACT FROM AUTHOR]

Abstract: Rock mass classification systems were first generated for use in engineering applications, but their potential for utilization in geomorphic studies has since been recognized. These techniques were mostly developed [...]

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1745-7939.2008.00123.x Byline: Heather L. Purdie (1), Martin S. Brook (2), Ian C. Fuller (2), John Appleby (2) Keywords: ablation; climate; Fox Glacier; hazards; velocity Abstract: Abstract: Seasonal variations in ablation and surface velocity were investigated on the lower Fox Glacier. Variations occur between summer and winter ablation, with surface velocity also showing marked seasonality. Recent advance has resulted in the glacier gaining around 200 m length since late 2004. Longer term, Fox Glacier appears linked to the Southern Oscillation Index, with positive glacier mass balances associated with negative Southern Oscillation Index (El Nino). An estimated glacier response time of approximately 9-14 years suggests the current terminus advance was linked to mass gains in the mid-1990s. Recent collapses at the terminal face continue to prove a hazard at this busy tourist destination. Author Affiliation: (1)School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand, (2)Geography Programme, School of People, Environment and Planning, Massey University, Palmerston North, New Zealand Article note: E-mail: hpurdie@xtra.co.nz

Space is used as a proxy for time in determining the role of glaciation in shaping valley cross profiles in the Two Thumb Range (Southern Alps), New Zealand. The range is undergoing rapid tectonic transport and uplift as it is advected toward the Alpine fault. Repeated cycles of glacial erosion during the Quaternary have fashioned U-shaped valleys in the north of the range, close to the Main Divide, while valleys in the less glaciated south of the range have rounded divides and convex fluvial cross profiles. Tectonic transport and uplift rates, coupled with an offshore oxygen isotope [[delta].sup.18]O) record and glacialgeological reconstructions, allow time constraints to be applied to valley development along the range. Valley width and depth measurements and power-law equations were used to quantify the shape of cross-profile transects in 37 valleys. Valleys evolved into a characteristic U-shaped cross profile formed over [greater than or equal to] 400 k.y. of glacial occupancy. This, regardless of other models of glacial flattening of valley long profiles, suggests that alpine glaciation excavates greater volumes of rock, indicating that glaciers are a more effective erosional agent than fluvial activity in alpine mountain belts. Keywords: glacial valleys, morphology, landscape evolution.

Mountain glaciers are useful climatic indicators in alpine regions where instrumental climate observations are sparse. Here we review the state of understanding of past and present glaciation in North Island, New Zealand. During the last glacial, mountain glaciers descended to ∼1200 m on both Ruapehu and Tongariro. Glacier modelling indicates that air temperatures during the Last Glacial Maximum were 5–7°C lower than present. Under such conditions, favourable topoclimatic mass balance processes (e.g. snowblow, shading) may have promoted marginal glaciation in lower-elevation North Island mountain ranges. The timing and magnitude of North Island glacier changes are broadly consistent with moraine chronologies and climatic reconstructions from glaciers in the Southern Alps. As of 2016, several glaciers and multi-year snow patches persist in North Island (totalling 3.0 km2 – a 25% reduction in area since 1988), all situated on the summit region of Ruapehu volcano. Mass balance of these glaciers is modulated by topoclimatic factors and debris cover, which may reduce rates of mass loss in the near term. However, given the proximity of the present equilibrium line altitude to the summit elevation of Ruapehu, complete loss of the present glaciers is probable under even moderate warming scenarios predicted for the coming decades. [ABSTRACT FROM AUTHOR]