ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Unknown

Spatial Dimensions of Public Policy (1978)

Hoare, Anthony ; Coppock, J. T. ; Sewell, W. R. D. ; [et al.]

Wiley

In: Geographical Journal. 1978; 144(2): 332. Published 1978 Jul 01. doi: 10.2307/634179.

add to mindlist on the mindlist

Details

Publication Date: 1978-07-01

Print ISSN: 0016-7398

Electronic ISSN: 1475-4959

Topics: Geography

Published by Wiley

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

PAPER CURRENT

S·F·X

Fulltext

2

Unknown

Seawater carbonate chemistry and phytoplankton biomass and species composition of a unique temperate rocky coastal hydrothermal vent system (2019)

Zitoun, Rebecca ; Connell, Sean D ; Cornwall, Christopher Edward ; [et al.]

PANGAEA

add to mindlist on the mindlist

Details

Publication Date: 2024-03-15

Description: In situ effects of ocean acidification are increasingly studied at submarine CO2 vents. Here we present a preliminary investigation into the water chemistry and biology of cool temperate CO2 vents near Whakaari–White Island, New Zealand. Water samples were collected inside three vent shafts, within vents at a distance of 2 m from the shaft and at control sites. Vent samples contained both seawater pH on the total scale (pHT) and carbonate saturation states that were severely reduced, creating conditions as predicted for beyond the year 2100. Vent samples showed lower salinities, higher temperatures and greater nutrient concentrations. Sulfide levels were elevated and mercury levels were at concentrations considered toxic at all vent and control sites, but stable organic and inorganic ligands were present, as deduced from Cu speciation data, potentially mediating harmful effects on local organisms. The biological investigations focused on phytoplankton, zooplankton and macroalgae. Interestingly, we found lower abundances but higher diversity of phytoplankton and zooplankton at sites in the direct vicinity of Whakaari. Follow-up studies will need a combination of methods and approaches to attribute observations to specific drivers. The Whakaari vents represent a unique ecosystem with considerable biogeochemical complexity, which, like many other vent systems globally, require care in their use as a model of 'future oceans'.

Keywords: Alkalinity, total; Ammonium; Ammonium, standard deviation; Aragonite saturation state; Bicarbonate ion; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cell density; CO2 vent; Coast and continental shelf; Community composition and diversity; Entire community; Equitability; Field measurement; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Nitrogen oxide; Nitrogen oxide, standard deviation; Number of species; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Phosphate; Phosphate, standard deviation; Salinity; Shannon Diversity Index; South Pacific; Station label; Temperate; Temperature, water; Type; Whakaari_White_Island

Type: Dataset

Format: text/tab-separated-values, 241 data points

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

DATA PANGAEA

S·F·X

Fulltext

3

Unknown

Seawater carbonate chemistry and sperm swimming performance and pHi in the New Zealand sea urchin Evechinus chloroticus (2022)

Hudson, Michael E ; Sewell, M A

PANGAEA

add to mindlist on the mindlist

Details

Publication Date: 2024-03-15

Description: In sea urchins, spermatozoa are stored in the gonads in hypercapnic conditions (pH〈7.0). During spawning, sperm are diluted in seawater of pH〉8.0, and there is an alkalinization of the sperm's internal pH (pHi) through the release of CO2 and H+. Previous research has shown that when pHi is above 7.2-7.3, the dynein ATPase flagellar motors are activated, and the sperm become motile. It has been hypothesised that ocean acidification (OA), which decreases the pH of seawater, may have a narcotic effect on sea urchin sperm by impairing the ability to regulate pHi, resulting in decreased motility and swimming speed. Here we use data collected from the same individuals to test the relationship between pHi and sperm motility/performance in the New Zealand sea urchin Evechinus chloroticus (Valenciennes) under near- (2100) and far-future (2150) atmospheric pCO2 conditions (RCP 8.5: pH 7.77, 7.51). Decreasing seawater pH significantly negatively impacted the proportion of motile sperm), and four of the six computer-assisted sperm analysis (CASA) sperm performance measures. In control conditions, sperm had an activated pHi of 7.52. E. chloroticus sperm could not defend pHi. in future OA conditions; there was a stepped decrease in the pHi at pH 7.77, with no significant difference in mean pHi between pH 7.77 and 7.51. Paired measurements in the same males showed a positive relationship between pHi and sperm motility, but with a significant difference in the response between males. Differences in motility and sperm performance in OA conditions may impact fertilization success in a future ocean.

Keywords: Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Aragonite saturation state, standard error; Average path velocity; Average path velocity, standard error; Benthic animals; Benthos; Bicarbonate ion; Calcite saturation state; Calcite saturation state, standard error; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); Curvilinear velocity; Curvilinear velocity, standard error; Echinodermata; Evechinus chloroticus; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Linearity; Linearity, standard error; Matheson_Bay_OA; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; pH; pH, standard error; Potentiometric titration; Progression; Progression, standard error; Reproduction; Salinity; Salinity, standard error; Single species; South Pacific; Species, unique identification; Species, unique identification (Semantic URI); Species, unique identification (URI); Spectrophotometric; Sperm motility; Sperm motility, standard error; Straight line velocity; Straight line velocity, standard error; Temperate; Temperature, water; Treatment; Type; Wobble; Wobble, standard error

Type: Dataset

Format: text/tab-separated-values, 123 data points

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

DATA PANGAEA

S·F·X

Fulltext

4

Unknown

Seawater carbonate chemistry and development and growth in early‑stage larvae of the endemic New Zealand sea urchin, Evechinus chloroticus (2021)

Sewell, M A ; Baker, Daniel ; Hudson, Michael E ; [et al.]

PANGAEA

add to mindlist on the mindlist

Details

Publication Date: 2024-03-15

Description: Under the ocean acidification (OA) conditions predicted for 2100, the larval stages of temperate sea urchins are smaller, with reduced and abnormal skeleton and changes in metabolic rate. Here, we measure the impact of near-future and long-term predictions of atmospheric pCO2 levels on the early development of the echinometrid sea urchin Evechinus chloroticus using single male:female crosses, effect sizes and a within-study meta-analysis. Using the developmental signpost of the 16-cell stage, we show a mean delay of 5.11 min at pH 7.7 and 11.85 min at pH 7.5, which may have flow-on effects to later embryo and larval stages. Echinopluteus larvae raised in OA conditions (pH 7.7, 7.5) were 5–10% smaller in body length and 10–12% smaller in arm length than controls. Metabolic rate was highly variable between single male:female crosses—increasing in some crosses, decreasing in others—with a non-significant effect size in the meta-analysis. Preliminary experiments suggest that metabolic rate changes may be impacted by loss of mitochondrial function at low pH. Single male:female crosses showed variable OA responses in all measurements, suggesting that when assessing the population-level impacts of OA on early development of sea urchins there is a need to include high levels of biological replication.

Keywords: Alkalinity, total; Alkalinity, total, standard error; Angle; Animalia; Aragonite saturation state; Aragonite saturation state, standard error; Arm length; Bicarbonate ion; Body length; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calcite saturation state, standard error; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Development; Echinodermata; Embryos; Evechinus chloroticus; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Identification; Laboratory experiment; Matheson_Bay; Metabolic rate of oxygen per individual; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; Pelagos; pH; pH, standard error; pH change; Potentiometric; Potentiometric titration; Proton leak rate; Registration number of species; Replicate; Respiration; Respiration rate, oxygen, per individual; Salinity; Salinity, standard error; Single species; South Pacific; Species; Symmetry; Temperate; Temperature, water; Temperature, water, standard error; Time in hours; Time in minutes; Treatment; Type; Uniform resource locator/link to reference; Width; Zooplankton

Type: Dataset

Format: text/tab-separated-values, 35354 data points

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

DATA PANGAEA

S·F·X

Fulltext

5

Unknown

Seismic response to evolving injection at the Rotokawa geothermal field, New Zealand (2020)

Hopp, C. ; Sewell, S. ; Mroczek, S. ; [et al.]

In: Geothermics

add to mindlist on the mindlist

Details

Publication Date: 2021-02-08

Description: Catalogs of microseismicity are routinely compiled at geothermal reservoirs and provide valuable insights into reservoir structure and fluid movement. Hypocentral locations are typically used to infer the orientations of structures and constrain the extent of the permeable reservoir. However, frequency-magnitude distributions may contain additional, and underused, information about the distribution of pressure. Here, we present a four-year catalog of seismicity for the Rotokawa geothermal field in the central Taupō Volcanic Zone, New Zealand starting two years after the commissioning of the 140 MWe Nga Awa Purua power station. Using waveform-correlation-based signal detection we double the size of the previous earthquake catalog, refine the location and orientation of two reservoir faults and identify a new structure. We find the rate of seismicity to be insensitive to major changes in injection strategy during the study period, including the injectivity decline and shift of injection away from the dominant injector, RK24. We also map the spatial distribution of the earthquake frequency-magnitude distribution, or b-value, and show that it increases from ∼1.0 to ∼1.5 with increasing depth below the reservoir. As has been proposed at other reservoirs, we infer that these spatial variations reflect the distribution of pressure in the reservoir, where areas of high b-value correspond to areas of high pore-fluid pressure and a broad distribution of activated fractures. This analysis is not routinely conducted by geothermal operators but shows promise for using earthquake b-value as an additional tool for reservoir monitoring and management.

Language: English

Type: info:eu-repo/semantics/article

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

PAPER (OA)

S·F·X

Overview

6

Unknown

Anisotropy as an indicator for reservoir changes: example from the Rotokawa and Ngatamariki geothermal fields, New Zealand (2020)

Mroczek, S. ; Savage, M. ; Hopp, C. ; [et al.]

In: Geophysical Journal International

add to mindlist on the mindlist

Details

Publication Date: 2020-12-08

Description: We investigate the relation between geothermal field production and fracture density and orientation in the Ngatamariki and Rotokawa geothermal fields, located in the Taupo Volcanic Zone, New Zealand using shear wave splitting (SWS). We determine the SWS parameters for 17 702 microseismic events across 38 stations spanning close to 4 yr from 2012 to 2015. We compare the strength of anisotropy to changes in field production and injection. We also compare the orientation of the anisotropy to in situ and regional measurements of maximum horizontal stress orientation. (⁠SHmax⁠). Due to the volume of unique events (approximately 160 000), shear wave phases are picked automatically. We carry out automatic SWS measurements using the Multiple Filter Automatic Splitting Technique (MFAST). The SWS measurements are interpreted in the context of stress aligned microcracks. Outside both fields and within Ngatamariki, fast polarizations align with the NE–SW regional orientation of SHmax⁠. Within Rotokawa a greater complexity is observed, with polarizations tending toward N–S. We observe increases in per cent anisotropy coinciding with the start of production/injection in Ngatamariki and then a later correlated drop in per cent anisotropy and vP/vS ratios in southern Ngatamariki as injection is shifted to the north. This relationship is consistent with pore fluid pressure within the reservoir being affected by local changes in production and injection of geothermal fluids causing cracks to open and close in response.

Language: English

Type: info:eu-repo/semantics/article

Format: application/pdf

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

PAPER (OA)

S·F·X

PDF

Overview

7

Unknown

Basement heterogeneity in the Cathaysia crustal block, southeast China (2007)

Fletcher, Chris J. N. ; Chan, Lung. S. ; Sewell, Roderick J. ; [et al.]

In: Geological Society Special Publication 226: 145-155.

add to mindlist on the mindlist

Details

Publication Date: 2007-10-08

Description: Isotope signatures and TDM model ages in Hong Kong and neighbouring Guangdong Province have indicated that the basement of the Cathaysia Block is probably an amalgamation of narrow crustal slices, ranging in age from latest Archaean to Mesoproterozoic. Inheritance ages from zircons contained within Mesozoic volcanic and plutonic rocks also show Proterozoic and Archaean components. Regional gravity survey studies display NNE- to NE-trending Bouguer anomalies that are indicative of sharp changes in rock densities at middle and lower crustal levels. The anomalies displayed on the gravity profile from Guangdong to Hong Kong have been modelled as narrow slices of Archaean and Proterozoic crust. A substantial E-W-trending Bouguer anomaly, which largely parallels the trend of the foliation in the Proterozoic schists of the region, is present to the east of Guangzhou. It is proposed that the basement of the Cathaysia Block consists of an amalgamation of NE- to NNE-trending Palaeo- to Mesoproterozoic and Archaean crustal terranes, which in places have retained the pre-amalgamation E-W-trending tectonic fabric. The discontinuities between the basement terranes, and the E-W structures have strongly influenced the geological evolution of the Phanerozoic sequences and igneous complexes in southeast China. These are most obviously manifest in the regional NE-trending fault and shear zones that displace the cover sequences.

Permalink