scholarly journals High-resolution relocation of aftershocks of the Mw7.1 Darfield, New Zealand, earthquake and implications for fault activity

2013 ◽  
Vol 118 (8) ◽  
pp. 4184-4195 ◽  
Author(s):  
E. M. Syracuse ◽  
C. H. Thurber ◽  
C. J. Rawles ◽  
M. K. Savage ◽  
S. Bannister
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Fault Activity

scholarly journals High-Resolution Vegetation Mapping Using eXtreme Gradient Boosting Based on Extensive Features

2019 ◽  
Vol 11 (12) ◽  
pp. 1505 ◽  
Author(s):  
Heng Zhang ◽  
Anwar Eziz ◽  
Jian Xiao ◽  
Shengli Tao ◽  
Shaopeng Wang ◽  
...  
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Large Scale ◽  
Field Survey ◽  
Terrestrial Ecosystems ◽  
Google Earth ◽  
Gradient Boosting ◽  
Global Changes ◽  
Vegetation Map ◽  
Extreme Gradient Boosting

Accurate mapping of vegetation is a premise for conserving, managing, and sustainably using vegetation resources, especially in conditions of intensive human activities and accelerating global changes. However, it is still challenging to produce high-resolution multiclass vegetation map in high accuracy, due to the incapacity of traditional mapping techniques in distinguishing mosaic vegetation classes with subtle differences and the paucity of fieldwork data. This study created a workflow by adopting a promising classifier, extreme gradient boosting (XGBoost), to produce accurate vegetation maps of two strikingly different cases (the Dzungarian Basin in China and New Zealand) based on extensive features and abundant vegetation data. For the Dzungarian Basin, a vegetation map with seven vegetation types, 17 subtypes, and 43 associations was produced with an overall accuracy of 0.907, 0.801, and 0.748, respectively. For New Zealand, a map of 10 habitats and a map of 41 vegetation classes were produced with 0.946, and 0.703 overall accuracy, respectively. The workflow incorporating simplified field survey procedures outperformed conventional field survey and remote sensing based methods in terms of accuracy and efficiency. In addition, it opens a possibility of building large-scale, high-resolution, and timely vegetation monitoring platforms for most terrestrial ecosystems worldwide with the aid of Google Earth Engine and citizen science programs.

scholarly journals A high-resolution modelling case study of a severe weather event over New Zealand

2008 ◽  
Vol 9 (3) ◽  
pp. 119-128 ◽  
Author(s):  
Stuart Webster ◽  
Michael Uddstrom ◽  
Hilary Oliver ◽  
Simon Vosper
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Severe Weather ◽  
Weather Event ◽  
Severe Weather Event

scholarly journals A Campaign for the Detection of Earth-Mass Planets in the Habitable Zone of Alpha Centauri

2012 ◽  
Vol 8 (S293) ◽  
pp. 58-64
Author(s):  
Robert A. Wittenmyer ◽  
Michael Endl ◽  
Christoph Bergmann ◽  
John Hearnshaw ◽  
Stuart I. Barnes ◽  
...  
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Optical Fibre ◽  
Orbital Stability ◽  
High Signal ◽  
Habitable Zone ◽  
Signal To Noise ◽  
Echelle Spectrograph ◽  
Doppler Method ◽  
Iodine Cell

AbstractWe review the possible formation and orbital stability of Earth-mass or super Earth-mass planets around either of the stars Alpha Centauri A or B and describe a program at Mt John University Observatory using the Doppler method that aims to detect such planets. From New Zealand, we are able to observe the Alpha Centauri system year-round. This is critical in order to acquire data of sufficient quantity and phase coverage to detect the orbit of a terrestrial-mass planet in the habitable zone. Our observations are being made at high resolution (R = 70,000) and high signal-to-noise with the Hercules vacuum echelle spectrograph attached to the 1-m McLellan telescope by a 25-m long optical fibre and using an iodine cell. We discuss the velocity precision and instrumental stability required for success and outline the progress of the observations so far. At present we are collecting about 10,000 observations of each star, A and B, per year with a typical precision of 2.5 m/s per observation.

scholarly journals Geographic distribution of restriction types ofMycobacterium bovisisolates from brush-tailed possums (Trichosurus vulpecula) in New Zealand

1986 ◽  
Vol 96 (3) ◽  
pp. 431-438 ◽  
Author(s):  
D. M. Collins ◽  
G. W. De Lisle ◽  
D. M. Gabric
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Restriction Enzymes ◽  
Restriction Endonuclease Analysis ◽  
Trichosurus Vulpecula ◽  
Typing System ◽  
Dna Restriction ◽  
Endonuclease Analysis

SUMMARYDNA restriction endonuclease analysis was used for intra-specific typing ofMycobacterium bovisisolates from 83 brush-tailed possums (Trichosurus vulpecula) obtained between 1982 and 1984 from the three major regions in New Zealand with endemic bovine tuberculosis. All the isolates were found to be genetically very similar. Differentiation of the isolates into 33 restriction types was achieved by using high-resolution electrophoresis and the combined results from separate digestions with the restriction enzymesBstEII,PvuII andBclI. The typing system was entirely reproducible. Isolates of the same type were usually found in adjacent localities and were always limited to one of the three major regions. In some cases, isolates of the same type were found in both 1982 and 1984. The phenotypic significance of the small genetic differences identified between different isolates is unknown. The typing system will be useful for monitoring the transmission ofM. bovisto other species and the future spread of differentM. bovistypes through possum populations.

scholarly journals Characterization of the complete mitochondrial genomes of two sibling species of parasitic roundworms, Haemonchus contortus and Teladorsagia circumcincta.

2020 ◽  
Author(s):  
Nikola Palevich ◽  
Paul Haydon Maclean ◽  
Young-Jun Choi ◽  
Makedonka Mitreva
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Haemonchus Contortus ◽  
Animal Health ◽  
Small Ruminants ◽  
Population Connectivity ◽  
Amino Acid Sequences ◽  
Strain Level ◽  
Teladorsagia Circumcincta ◽  
Geographical Regions

Abstract Background Haemonchus contortus and Teladorsagia circumcincta are among the two most pathogenic internal parasitic nematodes infecting small ruminants, such as sheep and goats, and are a global animal health issue. Accurate identification and delineation of Haemonchidae species is essential for development of diagnostic and control strategies with high resolution for Trichostrongyloidea infection in ruminants. Here, we describe in detail and compare the complete mitochondrial (mt) genomes of the New Zealand H. contortus and T. circumcincta field strains to improve our understanding of species- and strain-level evolution in these closely related roundworms. Methods In the present study, we performed extensive comparative bioinformatics analyses on the recently sequenced complete mt genomes of the New Zealand H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP field strains. Amino acid sequences inferred from individual genes of each of the two mt genomes were compared, concatenated and subjected to phylogenetic analysis using Bayesian inference (BI), Maximum Likelihood (ML) and Maximum Parsimony (MP).Results The AT-rich mt genomes of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP are 14,001 bp (A+T content of 77.4 %) and 14,081 bp (A+T content of 77.3 %) in size, respectively. All 36 of the typical nematode mt genes are transcribed in the forward direction in both species and comprise of 12 protein-encoding genes (PCGs), 2 ribosomal RNA (rrn) genes, and 22 transfer RNA (trn) genes. The secondary structures for the 22 trn genes and two rrn genes differ between H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP, however the gene arrangements of both are consistent with other Trichostrongylidea sequenced to date. Conclusions Comparative analyses of the complete mitochondrial nucleotide sequences, PCGs, A+T rich and non-coding repeat regions of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP further reinforces the high levels of diversity and gene flow observed among Trichostrongylidea, and supports their potential as ideal markers for strain-level identification from different hosts and geographical regions with high resolution for future studies. The complete mt genomes of H. contortus NZ_Hco_NP and T. circumcincta NZ_Teci_NP presented here provide useful novel markers for further studies of the meta-population connectivity and the genetic mechanisms driving evolution in nematode species.

scholarly journals The Geochemistry of Pāua as a Potential Proxy for Past and Present Environmental Change

2021 ◽  
Author(s):  
◽  
Ramona Mahia White
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
High Resolution ◽  
Temporal Resolution ◽  
Environmental Conditions ◽  
Winter Season ◽  
High Temporal Resolution ◽  
Nacreous Layer ◽  
Prismatic Layer ◽  
Icp Ms

<p>Nearshore New Zealand mollusca (shellfish) have the potential to be important archives of environmental conditions and change. Ambient ocean chemistry can be incorporated into the calcium carbonate (CaCO3) shell during the life span of the mollusc providing a high resolution temporal record of the chemical and physical changes of the environments the mollusc lived in. Previous studies on foraminifera and coral have shown that the substitution of magnesium or strontium for calcium (Mg, Sr/Ca) during the formation of the CaCO3 shell is directly correlated with ocean temperatures. Other divalent cations (e.g., Sr2+, Ba2+, Pb2+) can also provide information on ambient salinity, primary productivity or nutrient levels, and local anthropogenic pollution. This study uses new geochemical techniques that have been developed to measure the trace element chemistry of CaCO3 mollusc shells at high temporal resolution, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in order to calibrate shell chemistry with environmental conditions. This study is the first to explore the use of the geochemistry of Haliotis iris as a potential proxy for (paleo-) environmental conditions. Pāua (Haliotis iris) were collected from six different localities around New Zealand and the Chatham Islands as well as a cultured environment (OceaNZ Blue Ltd). The shells were sectioned following the axis of maximum growth exposing both CaCO3 layers; the prismatic (predominantly calcite) and nacreous (aragonite) layers. The shells were analysed by LA-ICP-MS at 25 μm spot sizes through a high temporal transect of both layers. Observed differences in the element/Ca ratios between the prismatic and nacreous layer reflect the differing crystallinity of each layer. High temporal resolution Mg/Ca ratio data of the prismatic layer of the samples which grew in a cultured environment were compared with temperature and growth data supplied by OceaNZ Blue Ltd. The results showed that temperature was not the primary control on the uptake of Mg within the shells and that influences from biological factors including increased growth rate were also evident. Sr/Ca ratios show a weak inverse relationship with increased growth rate assumed. These results, however, are not reproducible within samples collected from the wild, showing that external factors (high wave energy, diet, predation, lack of food) place metabolic stress on the pāua. The monitoring of other element/Ca including Ba/Ca, Al/Ca, Pb/Ca and Zn/Ca ratios have the potential to provide information into the past frequency of storm events that deliver sediment into the oceans and remobilise other sediments and changing levels of environmental pollution. This is reflected through increased Al/Ca, Pb/Ca and Zn/Ca ratios during the winter season in a number of samples (n = 3) gained from the high resolution analysis of the prismatic layers. Overall, element/Ca ratios are difficult to correlate environmental conditions in samples from the wild as there are many different parameters influencing the uptake of element/Ca ratios with the shells of pāua. Uncertainties lie with a lack of understanding of the biological controls influencing pāua during biomineralisation including the transportation of the elements within organism to the extrapallial fluid to be biomineralised, ontogeny, and the rate and regularity of biomineralisation of shell material.</p>

scholarly journals Development of a multi-method chronology spanning the Last Glacial Interval from Orakei maar lake, Auckland, New Zealand

Geochronology ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 367-410
Author(s):  
Leonie Peti ◽  
Kathryn E. Fitzsimmons ◽  
Jenni L. Hopkins ◽  
Andreas Nilsson ◽  
Toshiyuki Fujioka ◽  
...  
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Large Scale ◽  
Volcanic Eruptions ◽  
Climate System ◽  
Luminescence Dating ◽  
Reference Curve ◽  
Auckland Volcanic Field ◽  
Last Glacial ◽  
Maar Lake

Abstract. Northern New Zealand is an important location for understanding Last Glacial Interval (LGI) palaeoclimate dynamics, since it is influenced by both tropical and polar climate systems which have varied in relative strength and timing. Sediments from the Auckland Volcanic Field maar lakes preserve records of such large-scale climatic influences on regional palaeo-environment changes, as well as past volcanic eruptions. The sediment sequence infilling Orakei maar lake is continuous, laminated, and rapidly deposited, and it provides a high-resolution (sedimentation rate above ∼ 1 m kyr−1) archive from which to investigate the dynamic nature of the northern New Zealand climate system over the LGI. Here we present the chronological framework for the Orakei maar sediment sequence. Our chronology was developed using Bayesian age modelling of combined radiocarbon ages, tephrochronology of known-age rhyolitic tephra marker layers, 40Ar∕39Ar-dated eruption age of a local basaltic volcano, luminescence dating (using post-infrared–infrared stimulated luminescence, or pIR-IRSL), and the timing of the Laschamp palaeomagnetic excursion. We have integrated our absolute chronology with tuning of the relative palaeo-intensity record of the Earth's magnetic field to a global reference curve (PISO-1500). The maar-forming phreatomagmatic eruption of the Orakei maar is now dated to > 132 305 years (95 % confidence range: 131 430 to 133 180 years). Our new chronology facilitates high-resolution palaeo-environmental reconstruction for northern New Zealand spanning the last ca. 130 000 years for the first time as most NZ records that span all or parts of the LGI are fragmentary, low-resolution, and poorly dated. Providing this chronological framework for LGI climate events inferred from the Orakei sequence is of paramount importance in the context of identification of leads and lags in different components of the Southern Hemisphere climate system as well as identification of Northern Hemisphere climate signals.

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