scholarly journals Coastal Geomorphology, McMurdo Sound, Antarctica

1968 ◽  
Vol 7 (51) ◽  
pp. 449-478 ◽  
Author(s):  
Robert L. Nichols
Keyword(s):  
Sea Level ◽  
Elephant Seal ◽  
Coastal Geomorphology ◽  
Mcmurdo Sound ◽  
M 10

AbstractWell-developed elevated beaches. deltaic deposits, marine-boulder pavements and wave-washed bedrock surfaces are found from Cape Bernacchi north to Granite Harbour. The highest measured marine feature, an elevated beach at Dunlop Island, is 20 m (67 ft) above sea-level. The highest beaches at Marble Point and Cape Roberts, about 48 km (30 miles) apart, are about 20 m (66 ft) above sea-level. The marine limit between these two points is, therefore, essentially horizontal. The highest beach at Cape Bernacchi. approximately 4.8 km (3 miles) south of Marble Point, is about 12 m (40 ft) above sea-level, Well-developed elevated beaches disappear about 3.2 km (2 miles) south of Cape Bernacchi and are not found between this point and Koettlitz Glacier.These beaches post-date the youngest glaciation recognized in the lower Wright Valley. A 14C analysis of an elephant seal buried in a 13 m (44 ft) beach at Marble Point indicates that this beach is 4450 ± 150 years old. As sea-level at this time was approximately 3 m (10 ft) lower than at present. the Marble Point area has risen isostatically about 16 m (54 ft) during the last 4450 ± 150 years.Pitted beaches, beaches deposited on ice, a buried elephant seal and gravel ridges deposited by ice indicate that all of the beaches were formed in a climate like that now found in the area.

scholarly journals Coastal Geomorphology, McMurdo Sound, Antarctica

1968 ◽  
Vol 7 (51) ◽  
pp. 449-478 ◽  
Author(s):  
Robert L. Nichols
Keyword(s):  
Sea Level ◽  
Elephant Seal ◽  
Coastal Geomorphology ◽  
Mcmurdo Sound ◽  
M 10

Abstract Well-developed elevated beaches. deltaic deposits, marine-boulder pavements and wave-washed bedrock surfaces are found from Cape Bernacchi north to Granite Harbour. The highest measured marine feature, an elevated beach at Dunlop Island, is 20 m (67 ft) above sea-level. The highest beaches at Marble Point and Cape Roberts, about 48 km (30 miles) apart, are about 20 m (66 ft) above sea-level. The marine limit between these two points is, therefore, essentially horizontal. The highest beach at Cape Bernacchi. approximately 4.8 km (3 miles) south of Marble Point, is about 12 m (40 ft) above sea-level, Well-developed elevated beaches disappear about 3.2 km (2 miles) south of Cape Bernacchi and are not found between this point and Koettlitz Glacier. These beaches post-date the youngest glaciation recognized in the lower Wright Valley. A 14C analysis of an elephant seal buried in a 13 m (44 ft) beach at Marble Point indicates that this beach is 4450 ± 150 years old. As sea-level at this time was approximately 3 m (10 ft) lower than at present. the Marble Point area has risen isostatically about 16 m (54 ft) during the last 4450 ± 150 years. Pitted beaches, beaches deposited on ice, a buried elephant seal and gravel ridges deposited by ice indicate that all of the beaches were formed in a climate like that now found in the area.

Holocene relative sea levels and coastal changes in the lower Cree valley and estuary, SW Scotland, U.K.

2002 ◽  
Vol 93 (4) ◽  
pp. 301-331 ◽  
Author(s):  
D. E. Smith ◽  
J. M. Wells ◽  
T. M. Mighall ◽  
R. A. Cullingford ◽  
L. K. Holloway ◽  
...  
Keyword(s):  
Sea Level ◽  
Early Holocene ◽  
Coastal Geomorphology ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Levels ◽  
Coastal Changes

ABSTRACTChanges in Holocene (Flandrian) relative sea levels and coastal geomorphology in the lower Cree valley and estuary, SW Scotland, are inferred from detailed morphological and stratigraphical investigations. A graph of relative sea level changes is proposed for the area. Rising relative sea levels during the early Holocene were interrupted at c. 8300–8600 14C years B.P.(c. 9400–9900 calibrated years B.P.), when an extensive estuarine surface was reached at c. −1 m O.D., after which a fluctuating rise culminated at c. 6100–6500 14C B.P. (c. 7000–7500 calibrated years B.P.) in a prominent shoreline and associated estuarine surface measured at 7·7–10·3 m O.D. A subsequent fall in relative sea level was followed by a rise to a shoreline at 7·8–10·1 m O.D., exceeding or reoccupying the earlier shoreline over much of the area after c. 5000 14C B.P. (c. 5,800 calibrated years B.P.), before relative sea level fell to a later shoreline, reached after c. 2900 14C B.P. (c. 3100 calibrated years B.P.) at 5·5–8·0 m O.D., following which relative sea levels fell, ultimately reaching present levels. During these changes, a particular feature of the coastline was the development of a number of barrier systems. The relative sea level changes identified are compared with changes elsewhere in SW Scotland and their wider context is briefly considered.

Indurated sand horizon influences present day coastal geomorphology of nearshore Northern Moreton Bay, South-East Queensland, Australia

2020 ◽  
Author(s):  
Craig Heatherington ◽  
Simon Albert ◽  
Remo Cossu ◽  
Justine Kemp ◽  
Alistair Grinham
Keyword(s):  
Sea Level ◽  
Sand Dunes ◽  
Historical Context ◽  
Soil Formation ◽  
Coastal Geomorphology ◽  
Sea Levels ◽  
Moreton Bay ◽  
Core Samples ◽  
Marine Sand ◽  
Eastern Australia

<p>Sea-level rise will lead to substantial changes to coastal geomorphology over the coming century and it is imperative to understand the implications. This includes the underlying stratigraphic influences on seabed morphology and the historical context with which they have formed. On the densely populated coastline of Eastern Australia, coastal erosion is a significant concern for residents and stakeholders. In South East Queensland, and particularly the coastal zone surrounding Bribie Island spit in Northern Moreton Bay, the accelerated erosion of the spit and discovery of indurated sand horizons in nearshore regions both above and below the seabed create a convergence of the past influencing the present.</p><p>Indurated sand horizons are predominantly considered to be the relict B horizon of the pedogenic processes that formed a podosol soil profile. Whilst not ubiquitous under present sea level, their presence presents a unique opportunity to study an accessible palaeosol unaltered by further pedogenesis and carbon input (as opposed to terrestrial indurated sand formations). This allows for an analysis of a time in Northern Moreton Bay during lower sea levels and how these horizons affect present day morphology. Data acquisition consisted of high and low frequency acoustics, coupled with core samples for geological analysis.</p><p>Our results show the indurated sands buried under 1-2 m of marine sands sloping downwards to the east. This suggests the present-day seabed follows the contours of the sub-surface indurated sand. High-resolution bathymetry of exposed indurated sand outcrops near Bribie Island spit indicate a dune-like shape suggesting a formation from coastal sand dunes into active terrestrial soil during lower sea levels. The dune troughs having accumulated greater mineral and organic material than the peaks, which can be attributed to the former surviving inundation from rising sea levels and the latter having undergone a weaker pedogenesis and subsequently erosion. Exposed indurated sand outcrops with a vertical face or ‘scour step’ are elevated to the surrounding marine sand seabed. Similar elevated structures were found to be a barrier to onshore sediment transport from offshore deposits and limiting beach replenishment whilst also offering protection from dampening long period waves and large storm swells. Core samples taken through the indurated layer from behind the spit to the shipping channel offshore showed elevated levels of aluminium and iron compared to surrounding marine sands, and consistent with podosol soil formation.</p><p>The techniques used here suggest that historical terrestrial geomorphology has determined the shape, mineralogy and strength of indurated sand layers. As these indurated sand layers were submerged and further modified by present day sea level, they may play an important role in coastal geomorphology and protection as sea levels rise further in the coming century.</p>

Coastal Geomorphology and Sea-Level Change

2009 ◽  
Author(s):  
Iain Stewart ◽  
Christophe Morhange
Keyword(s):  
Sea Level ◽  
Mediterranean Basin ◽  
Sea Level Change ◽  
Coastal Geomorphology ◽  
Level Change ◽  
Shoreline Evolution ◽  
The Mediterranean ◽  
Coastal Features ◽  
The Mediterranean Basin ◽  
And Sea Level

The intricate shores of the Mediterranean Sea twist and turn for some 46,000 km, with three-quarters of their convoluted length confined to only four countries— Italy, Croatia, Greece, and Turkey. Just over half the coast is rocky, much of it limestone, with the remainder encompassing almost every type of littoral environment (exceptions being coral reefs and mangrove wetlands). Such littoral diversity has long made the seaboard of southern Europe, the Levant, and North Africa a fruitful natural laboratory for studying coastal geomorphology and sea-level change. The virtually enclosed sea ensures that wave processes are generally modest and the tidal range is limited (often less than half a metre), a combination that permits observational evidence of many modern shoreline features to be related precisely to mean sea level. Consequently, relative shifts in the position of now relict coastal features can be used to track the rhythms of relative sea-level change and shoreline evolution. Such rhythms have a bearing on several aspects beyond the physical geography of the Mediterranean basin: they inform archaeological reconstructions of the past settlement and exploitation of a coastal zone that has been an important focus of human activity since Palaeolithic times; they provide testing and fine-tuning for geophysical, geodynamic, and palaeoclimatic models for the region; and they set the backdrop to contemporary societal issues, such as future sea-level rise and coastline adjustments to mass tourism, which threaten the long-term sustainability of the Mediterranean littoral. In this chapter, we review these diverse facets of the Mediterranean coastal realm to provide a synthesis of how these shores have evolved into their present-day appearance. The Mediterranean occupies the convergence zone between two major tectonic plates, Africa and Europe, with a third, Arabia, pressing from the east. Caught within the collisional vice of these great plates are several minor plates and crustal blocks, most notably Anatolia and Apulia. The result is a complex network of plate tectonic structures that define the general configuration of the seaboard. In particular, two major subduction systems partition the Mediterranean basin into a patchwork of minor basins and subsidiary seas (Krijgsman 2002; Chapter 1).

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