scholarly journals GENERAL MODEL FOR ESTIMATION OF LONGSHORE TRANSPORT AT SHINGLE/MIXED BEACHES

2017 ◽  
pp. 26
Author(s):  
Giuseppe Roberto Tomasicchio ◽  
Felice D'Alessandro ◽  
Giuseppe Barbaro ◽  
Francesco Ciardulli ◽  
Antonio Francone ◽  
...  
Keyword(s):  
New Zealand ◽  
Field Experiment ◽  
General Model ◽  
Field Data ◽  
East Coast ◽  
Data Sets ◽  
Predictive Capability ◽  
Longshore Transport ◽  
Sand And Gravel ◽  
Gravel Beach

In the present study, the accuracy of the GLT model (Tomasicchio et al., 2013) has been verified for the estimation of the Longshore Transport (LT) at shingle/mixed beaches. In order to verify the suitability of the GLT model in determining LT estimates at shingle beaches, without any further calibration, the comparison between the LT predictions and observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991) has been considered. The comparison showed that the GLT predicted LT rates within a factor of 2 of the observed values. The predictive capability of the GLT has been also verified against an alternative general formula for the LT estimation at shingle beaches (Van Rijn, 2014). In addition, the suitability of the GLT model, even for the mixed beach case, has been assessed by means of the comparison between the LT prediction and the observation from a field experiment on a mixed sand and gravel beach at Hawke’s Bay, on the east coast of New Zealand (Komar, 2010).

Longshore transport of cobbles on a mixed sand and gravel beach, southern Hawke Bay, New Zealand

2011 ◽  
Vol 287 (1-4) ◽  
pp. 31-42 ◽  
Author(s):  
Mark E. Dickson ◽  
Paul S. Kench ◽  
Michael S. Kantor
Keyword(s):  
New Zealand ◽  
Longshore Transport ◽  
Sand And Gravel ◽  
Gravel Beach

Surface wave attenuation of seismic records with the co-core trace transform filter

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. V115-V128 ◽  
Author(s):  
Ning Wu ◽  
Yue Li ◽  
Baojun Yang
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Field Data ◽  
Wave Attenuation ◽  
Seismic Events ◽  
Data Sets ◽  
Transform Domain ◽  
Recent Developments ◽  
Seismic Records ◽  
Trace Transform

To remove surface waves from seismic records while preserving other seismic events of interest, we introduced a transform and a filter based on recent developments in image processing. The transform can be seen as a weighted Radon transform, in particular along linear trajectories. The weights in the transform are data dependent and designed to introduce large amplitude differences between surface waves and other events such that surface waves could be separated by a simple amplitude threshold. This is a key property of the filter and distinguishes this approach from others, such as conventional ones that use information on moveout ranges to apply a mask in the transform domain. Initial experiments with synthetic records and field data have demonstrated that, with the appropriate parameters, the proposed trace transform filter performs better both in terms of surface wave attenuation and reflected signal preservation than the conventional methods. Further experiments on larger data sets are needed to fully assess the method.

Tectonic and paleoclimatic significance of Quaternary river terraces of the Waipaoa river, east coast, North Island, New Zealand

2000 ◽  
Vol 43 (2) ◽  
pp. 229-245 ◽  
Author(s):  
Kelvin Berryman ◽  
Michael Marden ◽  
Dennis Eden ◽  
Colin Mazengarb ◽  
Yoko Ota ◽  
...  
Keyword(s):  
New Zealand ◽  
East Coast ◽  
River Terraces ◽  
Paleoclimatic Significance

Motukoreaite, a new hydrated carbonate, sulphate, and hydroxide of Mg and Al from Auckland, New Zealand

1977 ◽  
Vol 41 (319) ◽  
pp. 389-390
Author(s):  
K. A. Rodgers ◽  
J. E. Chisholm ◽  
R. J. Davis ◽  
C. S. Nelson
Keyword(s):  
New Zealand ◽  
Olivine Basalt ◽  
Unit Cell ◽  
Rock Fragments ◽  
Alkali Olivine Basalt ◽  
Beach Rock ◽  
Wet Chemical ◽  
O 19 ◽  
Olivine Sand ◽  
Sand And Gravel

Motukoreaite occurs as relatively abundant, white, clay-like cement in both beach-rock and basaltic volcanic tuffs on the flanks of a small, extinct, late Pleistocene, basaltic cone at Brown's Island (Motukorea), within Waitemata Harbour, Auckland, New Zealand (36° 50′ S., 174° 35′ E.). The occurrence was originally recorded by Bartrum (1941) as ‘beach limestone’ found at two places of the island's shore. The beach-rock consists of a grain-supported fabric of poorly sorted, well-rounded, alkali-olivine basalt pebbles and granules, subangular to sub-rounded fresh olivine sand and abraded sand- and gravel-sized bioclasts in a colourless to pale yellow-green aphanocrystalline matrix of motukoreaite. Additional detritals include quartz, feldspar, and sedimentary rock fragments. Stereoscan examination of the surface of pieces of the cement prised from the beach-rock showed a box-work of plate-like crystals with a hexagonal form in which individuals measured about 3×3×0·02 microns (fig. 1).Wet-chemical analysis of a separate of the cement containing some 5 % quartz and traces of calcite and goethite gives SiO2 5·55, Al2O3 17·87, Fe2O3 0·73, CaO 0·92, MgO 22·98, MnO 0·70, ZnO 0·56, Na2O 0·71, K2O 0·10, CO2 9·32, SO3 10·00, H2O+ 19·62, H2O- 10·35, sum 99·41 %. The unit-cell formula using obtained unit-cell constants and measured specific gravity 1·43) is (Na0·73K0·07)∑0·80(Mg18·13Mn0·32Zn0·21)∑18·66Al11·15(CO3)6·22(SO4)3·97 (OH)51·1927·20H2O. Of several idealized formulae that may be proposed NaMg19Al12(CO3)6.5 (SO4)4(OH)54·28H2O is preferred.

The Recent Cypraeidae of Northern New Zealand from the Kermadec Islands to the Poor Knights Islands, Southwest Pacific Ocean (Mollusca: Gastropoda: Cypraeidae)

The Festivus ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 36-54
Author(s):  
John Daughenbaugh
Keyword(s):  
New Zealand ◽  
Pacific Ocean ◽  
Continental Shelf ◽  
East Coast ◽  
Species Distributions ◽  
East Side ◽  
Tropical Eastern Pacific ◽  
The North ◽  
The Poor ◽  
Coastal Shelf

For researchers, isolated regions at the periphery of species’ distributions hold a peculiar fascination. The causes of their remoteness vary based on: distance (e.g. the Tropical Eastern Pacific), distance and countervailing currents (e.g. the Marquesas), location in a present day gyre (e.g. the Pitcairn Group) or the absence of present day means of veliger transport (e.g. the Vema Seamount). (Daughenbaugh & Beals 2013; Daughenbaugh 2015a & b, 2017). The northern New Zealand Region from the Kermadec Islands (Kermadecs) to the coastal and shelf areas in the northernmost part of New Zealand’s North Island (Northland), including the Poor Knights Islands (PKI), constitute the distributional boundaries for a number of Cypraeidae species. The boundaries are the result of the absence of coastal shelves along the east side of the Kermadec Ridge (Ridge) and precipitous drops to abyssal depths along Northland’s east coast continental shelf. Tropical waters, with their potential to transport Cypraeidae larvae, flow eastward from southern Queensland, Australia, entrained in the Tasman Front which terminates when reaching North Cape, the northernmost tip of Northland. There, the North Cape Eddy captures most of this flow while the remainder, the East Auckland Current (EAUC), flows intermittently southward along the eastern coastal, shelf and offshore areas of Northland into waters incapable of supporting Cypraeidae populations.

LUCERNE IN THE WELLINGTON, TARANAKI, AND EAST COAST DISTRICTS

1936 ◽  
pp. 92-95
Author(s):  
A.G. Elliott ◽  
T.W. Lonsdale
Keyword(s):  
New Zealand ◽  
West Coast ◽  
East Coast ◽  
General Trend ◽  
Present Position ◽  
Department Of Agriculture ◽  
Forage Crop ◽  
High Rainfall ◽  
The North ◽  
Subsequent Discussion

IN two papers read by officers of the Department of Agriculture at the 1936 conference of the New Zealand Grassland Association, the growing of lucernc as a forage crop in districts of relatively high rainfall was dealt with. The area covered by the papers included the Manawatu and west coast from Paraparaumu to the Patea River(I) and Taranaki(n). During the subsequent discussion on these and other papers the present position and general trend in regard to lucernegrowing in the Wairarapa, Eiawke's Eay, and Poverty Bay districts were also touched on. It is the intention here. to review briefly some of the more important points in regard to the cultivation of lucerne in the southern portion of the North Island as discussed at the conference.

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