Age determinations on sediment cores from the North Atlantic

Sediments in the North Atlantic ocean contain as eries of layers that are rich in ice-rafted debris and unusally poor in foraminifera. Here we present evidence that the most recent six of the 'Heinrich layers', deposited between 14,000 and 70,000 years ago, record marked decreases in sea surface temperature and salinity, decreases in the flux of planktonic forminifera to the sediments, and short-lived, massive discharges of icebergs originating in eastern Canada. The path of the icebergs, clearly marked by the presence of ice-rafted detrital carbonate, can be traced for more than 3,000 km - a remarkable distance, attesting to extreme cooling of surface waters and enormous amounts of drifiting ice. The cause of these extreme events is puzzling. They may reflect repated rapid advances of the Laurentide ice sheet, perhaps associated with reductions in air temperatures, yet temperature records from Greenland ice cores appear to exhibit only a weak corresponding signal. Moreover, the 5-10,000-yr intervals between the events are inconsistent with Milankovitch orbital periodicities, raising the question of what the ultimate cause of the postulated cooling may have been.

Chlorophyll-a, primary production rates, carbon concentrations and cell counts of coccolithophores, diatoms and microzooplankton measured in water samples from the North Atlantic during the M87/1 cruise in April 2012

The Deep Convection cruise repeatedly sampled two locations in the North Atlantic, sited in the Iceland and Norwegian Basins, onboard the RV Meteor (19 March - 2 May 2012). Samples were collected from multiple casts of a conductivity-temperature-depth (CTD) - Niskin rosette at each station. Water samples for primary production rates, community structure, chlorophyll a [Chl a], calcite [PIC], particulate organic carbon [POC] and biogenic silicic acid [BSi] were collected from predawn casts from six light depths (55%, 20%, 14%, 7%, 5% and 1% of incident PAR). Additional samples for community structure and ancillary parameters were collected from a second cast. Carbon fixation rates were determined using the 13C stable isotope method. Water samples for diatom and micro zooplankton counts, collected from the predawn casts, were preserved with acidic Lugol's solution (2% final solution) and counted using an inverted light microscope. Water samples for coccolithophore counts were collected onto cellulose nitrate filters and counted using polarising light microscopy. Water samples for Chl a analysis were filtered onto MF300 and polycarbonate filters and extracted in 90% acetone. PIC and BSi samples were filtered onto polycarbonate filters and analysed using an inductively coupled plasma emission optical spectrometer and a SEAL QuAAtro autoanalyser respectively.

Annotated record of the detailed examination of Mn deposits from the H.M.S. Penguin expedition to the Coral Sea

The analyses of the samples from the Balfour Shoal show that these deposits contain a very large quantity of carbonate of lime, ranging from 88.7 per cent, on the summit to 71.9 per cent, in the deeper water at the base of the cone. The decrease in the quantity of carbonate of lime with increase of depth is not quite regular; still, a general fall in the percentage of lime is clearly indicated from shallower to deeper water. As might be expected in such a circumscribed area, there is a great uniformity both in the chemical composition and relative abundance of the organic and inorganic constituents of the deposits. In all cases the carbonate of lime is almost wholly made up of the dead shells which have fallen from the surface waters - belonging to Plankton organisms such as Pteropods, Heteropods, pelagic Foraminifera and coccoliths. The calcareous shells were in very many cases discoloured brown or black by depositions of the peroxide of manganese. On the north-east steep side of the Balfour Shoal there were indications that depositions of manganese peroxide were more abundant than elsewhere. In 1645 fathoms, there was an angular fragment of a mottled yellowish jasper coated with manganese peroxide, and in 1570 fathoms there were three characteristic spherical black manganese nodules from one-half to three-fourths of an inch in diameter, quite similar to those procured by the Challenger in many areas of the Pacific and Atlantic. In one of these nodules the nucleus was a sub-angular fragment of a light-coloured augite-granophyre.

Warmer, deeper and greener mixed layers in the north Atlantic subpolar gyre over the last 50 years.

Shifts in global climate resonate in plankton dynamics, biogeochemical cycles, and marine food webs. We studied these linkages in the North Atlantic subpolar gyre (NASG), which hosts extensive phytoplankton blooms. We show that phytoplankton abundance increased since the 1960s in parallel to a deepening of the mixed layer and a strengthening of winds and heat losses from the ocean, as driven by the low frequency of the North Atlantic Oscillation (NAO). In parallel to these bottom-up processes, the top-down control of phytoplankton by copepods decreased over the same time period in the western NASG, following sea surface temperature changes typical of the Atlantic Multi-decadal Oscillation (AMO). While previous studies have hypothesized that climate-driven warming would facilitate seasonal stratification of surface waters and long-term phytoplankton increase in subpolar regions, here we show that deeper mixed layers in the NASG can be warmer and host a higher phytoplankton biomass. These results emphasize that different modes of climate variability regulate bottom-up (NAO control) and top-down (AMO control) forcing on phytoplankton at decadal timescales. As a consequence, different relationships between phytoplankton, zooplankton, and their physical environment appear subject to the disparate temporal scale of the observations (seasonal, interannual, or decadal). The prediction of phytoplankton response to climate change should be built upon what is learnt from observations at the longest timescales.

Warmer, deeper and greener mixed layers in the north Atlantic subpolar gyre over the last 50 years.

Shifts in global climate resonate in plankton dynamics, biogeochemical cycles, and marine food webs. We studied these linkages in the North Atlantic subpolar gyre (NASG), which hosts extensive phytoplankton blooms. We show that phytoplankton abundance increased since the 1960s in parallel to a deepening of the mixed layer and a strengthening of winds and heat losses from the ocean, as driven by the low frequency of the North Atlantic Oscillation (NAO). In parallel to these bottom-up processes, the top-down control of phytoplankton by copepods decreased over the same time period in the western NASG, following sea surface temperature changes typical of the Atlantic Multi-decadal Oscillation (AMO). While previous studies have hypothesized that climate-driven warming would facilitate seasonal stratification of surface waters and long-term phytoplankton increase in subpolar regions, here we show that deeper mixed layers in the NASG can be warmer and host a higher phytoplankton biomass. These results emphasize that different modes of climate variability regulate bottom-up (NAO control) and top-down (AMO control) forcing on phytoplankton at decadal timescales. As a consequence, different relationships between phytoplankton, zooplankton, and their physical environment appear subject to the disparate temporal scale of the observations (seasonal, interannual, or decadal). The prediction of phytoplankton response to climate change should be built upon what is learnt from observations at the longest timescales.

Climate change-related regime shifts have altered spatial synchrony of plankton dynamics in the North Sea

During the 1980s, the North Sea plankton community underwent a well-documented ecosystem regime shift, including both spatial changes (northward species range shifts) and temporal changes (increases in the total abundances of warmer water species). This regime shift has been attributed to climate change. Plankton provide a link between climate and higher trophic-level organisms, which can forage on large spatial and temporal scales. It is therefore important to understand not only whether climate change affects purely spatial or temporal aspects of plankton dynamics, but also whether it affects spatiotemporal aspects such as metapopulation synchrony. If plankton synchrony is altered, higher trophic-level feeding patterns may be modified. A second motivation for investigating changes in synchrony is that the possibility of such alterations has been examined for few organisms, in spite of the fact that synchrony is ubiquitous and of major importance in ecology. This study uses correlation coefficients and spectral analysis to investigate whether synchrony changed between the periods 1959–1980 and 1989–2010. Twenty-three plankton taxa, sea surface temperature (SST), and wind speed were examined. Results revealed that synchrony in SST and plankton was altered. Changes were idiosyncratic, and were not explained by changes in abundance. Changes in the synchrony of Calanus helgolandicus and Para-pseudocalanus spp appeared to be driven by changes in SST synchrony. This study is one of few to document alterations of synchrony and climate-change impacts on synchrony. We discuss why climate-change impacts on synchrony may well be more common and consequential than previously recognized.

Climate change-related regime shifts have altered spatial synchrony of plankton dynamics in the North Sea

During the 1980s, the North Sea plankton community underwent a well-documented ecosystem regime shift, including both spatial changes (northward species range shifts) and temporal changes (increases in the total abundances of warmer water species). This regime shift has been attributed to climate change. Plankton provide a link between climate and higher trophic-level organisms, which can forage on large spatial and temporal scales. It is therefore important to understand not only whether climate change affects purely spatial or temporal aspects of plankton dynamics, but also whether it affects spatiotemporal aspects such as metapopulation synchrony. If plankton synchrony is altered, higher trophic-level feeding patterns may be modified. A second motivation for investigating changes in synchrony is that the possibility of such alterations has been examined for few organisms, in spite of the fact that synchrony is ubiquitous and of major importance in ecology. This study uses correlation coefficients and spectral analysis to investigate whether synchrony changed between the periods 1959–1980 and 1989–2010. Twenty-three plankton taxa, sea surface temperature (SST), and wind speed were examined. Results revealed that synchrony in SST and plankton was altered. Changes were idiosyncratic, and were not explained by changes in abundance. Changes in the synchrony of Calanus helgolandicus and Para-pseudocalanus spp appeared to be driven by changes in SST synchrony. This study is one of few to document alterations of synchrony and climate-change impacts on synchrony. We discuss why climate-change impacts on synchrony may well be more common and consequential than previously recognized.

A map of North America : from the latest surveys and maps /

Relief shown pictorially.

Politics and protestant Lordship in North East Scotland during the reign of James VI: The life of George Keith, fourth Earl Marischal, 1554-1623

George Keith, fourth Earl Marischal is a case study of long-term, quietly successful and stable lordship through the reign of James VI. Marischal’s life provides a wholly underrepresented perspective on this era, where the study of rebellious and notorious characters has dominated. He is also a counter-example to the notion of a general crisis among the European nobility, at least in the Scottish context, as well as to the notion of a ‘conservative’ or ‘Catholic’ north east. In 1580 George inherited the richest earldom in Scotland, with a geographical extent stretching along the east coast from Caithness to East Lothian. His family came to be this wealthy as a long term consequence of the Battle of Flodden (1513) where a branch of the family, the Inverugie Keiths had been killed. The heiress of this branch was married to the third earl and this had concentrated a large number of lands, and consequently wealth, in the hands of the earls. This had, however, also significantly decreased the number of members and hence power of the Keith kindred. The third earl’s conversion to Protestantism in 1544 and later his adherence to the King’s Party during the Marian Civil War forced the Keiths into direct confrontation with their neighbours in the north east, the Gordons (led by the Earls of Huntly), a Catholic family and supporters of the Queen’s Party. Although this feud was settled for a time at the end of the war, the political turmoil caused by a succession of short-lived factional regimes in the early part of the personal reign of James VI (c.1578-1585) led the new (fourth) Earl Marischal into direct confrontation with the new (sixth) Earl of Huntly. Marischal was outclassed, outmanoeuvred and outgunned at both court and in the locality in this feud, suffering considerably. However, Huntly’s over-ambition in wider court politics meant that Marischal was able to join various coalitions against his rival, until Huntly was exiled in 1595. Marischal also came into conflict briefly with Chancellor John Maitland of Thirlestane as a consequence of Marischal’s diplomatic mission to Denmark in 1589-1590, but was again outmatched politically and briefly imprisoned. Both of these feuds reveal Marischal to be relatively cautious and reactionary, and both reveal the limitations of his power. Elsewhere, the study of Marischal’s activities in the centre of Scottish politics reveal him to be unambitious. He was ready to serve King James, the two men having a healthy working relationship, but Marischal showed no ambition as a courtier, to woo the king’s favour or patronage, instead delegating interaction with the monarch to his kinsmen. Likewise, in government, Marischal rarely attended any of the committees he was entitled to attend, such as the Privy Council, although he did keep a keen eye on the land market and the business conducted under the Great Seal. Although personally devout and a committed Protestant, the study of Marischal’s interaction with the national Kirk and the parishes of which he was patron reveal that he was at times a negligent patron and exercised his right of ministerial presentation as lordly, not godly patronage. The notion of a ‘conservative North East’ is, however, rejected. Where Marischal was politically weak at court and weak in terms of force in the locality, we see him pursuing sideways approaches to dealing with this. Thus he was keen to build up his general influence in the north and in particular with the burgh of Aberdeen (one result of this being the creation of Marischal College in 1593), pursued disputes through increasing use of legal methods rather than bloodfeud (thus exploiting his wealth and compensating for his relative lack of force) and developed a sophisticated system of maritime infrastructure, ultimately expressed through the creating of the burghs of Peterhead and Stonehaven. Although his close family caused him a number of problems over his lifetime, he was able to pass on a stable and enlarged lordship to his son in 1623.

Map of valuable property in the 6th ward of the city of Brooklyn belonging to John Dikeman & others to be sold by Franklin & Jenkins on Monday, 29th August, 1836 at 12 o'colck at their sales room, 15 Broad St.

Scale not given.

A map of North Carolina : from the best authorities /

Relief shown by hachures.