Climate and Holocene culture change: some practical problems

In recent years, not least through tree-ring studies for the Holocene and studies of oxygen isotope ratios in Foramenifera in deep-sea cores for the Pleistocene, both linked with radioactive chronometry, useful and well-dated information has become available for global temperature variations. Yet we seem at present little closer to understanding the climatic influences upon human settlement, or upon such major episodes in human existence as the agricultural revolution or the emergence of pastoral economies. In making reference to the developments in archaeological survey techniques over the past 20 years, and the increasing collaboration with geomorphologists and settlement geographers, I seek to highlight the gap in the chain of argument between data for global climatic parameters and impact on human communities. Where are the phytologists, the ecologists, the crop plant geographers? Where is the necessary focus upon the crucial themes of changing microclimates and changing agricultural productivity for specific species? An attempt is made to define more closely this deficiency.

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 321
Author(s):  
Maria Orfanoudaki ◽  
Anja Hartmann ◽  
Julia Mayr ◽  
Félix L. Figueroa ◽  
Julia Vega ◽  
...  

This study presents the validation of a high-performance liquid chromatography diode array detector (HPLC-DAD) method for the determination of different mycosporine-like amino acids (MAAs) in the red alga Bostrychia scorpioides. The investigated MAAs, named bostrychines, have only been found in this specific species so far. The developed HPLC-DAD method was successfully applied for the quantification of the major MAAs in Bostrychia scorpioides extracts, collected from four different countries in Europe showing only minor differences between the investigated samples. In the past, several Bostrychia spp. have been reported to include cryptic species, and in some cases such as B. calliptera, B. simpliciuscula, and B. moritziana, the polyphyly was supported by differences in their MAA composition. The uniformity in the MAA composition of the investigated B. scorpioides samples is in agreement with the reported monophyly of this Bostrychia sp.


2015 ◽  
Vol 32 (1) ◽  
pp. 149-170 ◽  
Author(s):  
Cara Nine

Abstract:Up until now, political philosophy has explained the acquisition of natural resources, in one way or another, through the terms of human settlement. An agent acquires natural resources by moving into the geographic area that contains these resources. Even how we make claims to the ocean floor depends on settlement — claimants must be adjacent to settled land. This essay extends original acquisition theories so that they can respond to cases that do not presuppose any conditions of human settlement. I suggest that resource rights in the deep sea may be created, alternatively, through acts of compromise. Compromise can alleviate conflict, allowing for claimants to move beyond stalemate to acquire goods. It also allows for a large degree of flexibility in the specification of rights, and thereby can explain nontraditional rights over areas of migration. The tricky part of a theory that grants rights through agreement is explaining why external parties, those not part of the agreement, have a duty to respect those rights. A compromise under certain conditions, I argue, places all persons under a duty to respect the rights created by the compromise. Thus, when two parties compromise, they may acquire goods from the commons — creating a duty for all others to respect the parties’ rights over these goods. Importantly, rights created through compromise are constrained by a set of concerns for those excluded.


1972 ◽  
Vol 2 (3) ◽  
pp. 270-273 ◽  
Author(s):  
Cesare Emiliani

Oxygen isotopic analysis and absolute dating of deep-sea cores show that temperatures as high as those of today occurred for only about 10% of the time during the past half million years. The shortness of the high temperature intervals (“hypsithermals”) suggests a precarious environmental balance, a condition which makes man's interference with the environment during the present hypsithermal extremely critical. This precarious balance must be stabilized if a new glaciation or total deglaciation is to be avoided.


Author(s):  
Matthias Golz ◽  
Florin Boeck ◽  
Sebastian Ritz ◽  
Gerd Holbach

The efforts to discover the world’s oceans — even in extremely deep-sea environments — have grown more and more in the past years. In this context, unmanned underwater vehicles play a central role. Underwater systems that are not tethered need to provide an apparatus to ensure a safe return to the surface. Therefore, positive buoyancy is required and can be achieved by either losing weight or expanding volume. A conservative method is the dropping of ballast weight. However, nowadays this method is not appropriate due to the environmental impact. This paper presents a ballast system for an automated ascent of a deep-sea seabed station in up to 6000 m depth. The ballast system uses a DC motor driven modified hydraulic pump and a compressed air auxiliary system inside a pressure vessel. With regard to the environmental contamination in case of a leakage, only water is used as ballast fluid. The modification of an ordinary oil-hydraulic radial piston pump and the set-up of the ballast system is introduced. Results from sea trials in the Atlantic Ocean are presented to verify the functionality of the ballast system.


Author(s):  
A. L. Rice ◽  
D. S. M. Billett ◽  
J. Fry ◽  
A. W. G. John ◽  
R. S. Lampitt ◽  
...  

SynopsisEvidence has accumulated over the past twenty years to suggest that the deep-sea environment is not as constant as was at one time thought, but exhibits temporal variations related to the seasonally in the overlying surface waters. Recent results from deep-moored sediment traps suggest that this coupling is mediated through the sedimentation of organic material, while observations in the Porcupine Seabight indicate that in this region, at least, there is a major and rapid seasonal deposition of aggregated phytodetritus to the sea-floor at slope and abyssal depths.This paper summarises the results of the Porcupine Seabight studies over the past five years or so, using time-lapse sea-bed photography and microscopic, microbiological and chemical analyses of samples of phytodetritus and of the underlying sediment. The data are to some extent equivocal, but they suggest that the seasonal deposition is a regular and dramatic phenomenon and that the material undergoes relatively little degradation during its passage through the water column. The mechanisms leading to the aggregation of the phytodetritus have not been identified, and it is not yet known whether the phenomenon is geographically widespread nor whether it is of significance to the deep-living mid-water and benthic communities.


1982 ◽  
Vol 1 (18) ◽  
pp. 97
Author(s):  
J. Zacks

The cost of many coastal projects is often increased by the expensive beach repair and maintenance required to remedy the destabilising effects of structures on the adjoining coastline. Physical and/or mathematical models have been developed for use in planning these projects in order to predict and quantify the effects of marine sediment transport on the coastal topography. Such models need to be calibrated against prototype data and one method of gauging volumetric sediment movement is by successive bathymetric/ topographic profiting surveys which are performed seasonally and annually. Since large quantities of sediment are related to small changes in bed elevation it is clear that this profiling needs to be done with the utmost precision* The areas most affected extend from the beach through the surf zone to water depths of about 25 metres. The surf zone in particular is a dynamic and hostile area which falls outside the traditional activities of both the hydrographic and land surveyors. Consequently innovative methods, deficient in sound survey principle and practice, have often been pursued in this area without any attempt being made to assess the tolerance on the data. This paper attempts to show that it is possible to produce reliable and verifiable results to the required accuracy by using conventional survey equipment and techniques, also by taking the necessary precautions against the many possible sources of survey error. The procedures and techniques described have evolved from NRIO's involvement over the past decade in major projects at Richards Bay, Durban, Koeberg and in False Bay. The results of a recent verification investigation are fully reported in this paper.


1988 ◽  
Vol 10 ◽  
pp. 178-182 ◽  
Author(s):  
Lonnie G. Thompson ◽  
Wu Xiaoling ◽  
Ellen Mosley-Thompson ◽  
Xie Zichu

Results from the first glaciological investigation of the Dunde ice cap demonstrate that a long, highly temporally resolvable climatic ice-core record is preserved in this ice cap. Measurements of stratigraphy, microparticle concentrations, liquid conductivity, and oxygen-isotope ratios from three snow pits in 1984 suggest that the annual accumulation is approximately 200 mm (water equivalent). Measurement of microparticle concentrations and conductivities of pit samples collected in 1986 confirm the existence of annual dust layers and an annual accumulation rate of ∼200 mm/year over the past 5 years. Bore-hole temperatures of –5.4°C at 30 m indicate that the ice cap is polar. Mono-pulse radar depth determinations yield an average thickness of 140 m, which (coupled with the smooth bedrock topography and the current accumulation rate) suggest that the Dunde ice cap should contain at least a 3000 year climatic record. A drilling program to recover that record from this subtropical location is planned for 1987.


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