Oxygen isotope ratios in the shell of Mytilus edulis: archives of glacier meltwater in Greenland?

Melting of the Greenland Ice Sheet (GrIS) is accelerating and will contribute significantly to global sea level rise during the 21st century. Instrumental data on GrIS melting only cover the last few decades, and proxy data extending our knowledge into the past are vital for validating models predicting the influence of ongoing climate change. We investigated a potential meltwater proxy in Godthåbsfjord (West Greenland), where glacier meltwater causes seasonal excursions with lower oxygen isotope water (δ18Ow) values and salinity. The blue mussel (Mytilus edulis) potentially records these variations, because it precipitates its shell calcite in oxygen isotopic equilibrium with ambient seawater. As M. edulis shells are known to occur in raised shorelines and archaeological shell middens from previous Holocene warm periods, this species may be ideal in reconstructing past meltwater dynamics. We investigate its potential as a palaeo-meltwater proxy. First, we confirmed that M. edulis shell calcite oxygen isotope (δ18Oc) values are in equilibrium with ambient water and generally reflect meltwater conditions. Subsequently we investigated if this species recorded the full range of δ18Ow values occurring during the years 2007 to 2010. Results show that δ18Ow values were not recorded at very low salinities (< ~ 19), because the mussels appear to cease growing. This implies that Mytilus edulis δ18Oc values are suitable in reconstructing past meltwater amounts in most cases, but care has to be taken that shells are collected not too close to a glacier, but rather in the mid-region or mouth of the fjord. The focus of future research will expand on the geographical and temporal range of the shell measurements by sampling mussels in other fjords in Greenland along a south–north gradient, and by sampling shells from raised shorelines and archaeological shell middens from prehistoric settlements in Greenland.

‘Warsaw Pact Military Doctrines in the 70s and 80s: Findings in the East German Archives’

This article draws on Warsaw Treaty Organisation and East German military archives to demonstrate that the WTO's military exercises until the mid-1990s always envisaged an offensive strategy with the aim of reaching the Channel in a few days. Only gradually did this change under Gorbachev and to include also defensive strategies, very much against the opposition of East Germany.

'The house of books': libraries and archives in Ancient Egypt

In 1957, John Sperry Jr. published an article in Libri entitled “Egyptian libraries: a survey of the evidence.” Some 55 years on, this article revisits the subject, taking into account research undertaken in the field of Egyptology over the last half a century. Based on an extended essay written for the online Certificate in Egyptology course at the University of Manchester, this article considers the evidence for the existence of “institutional” (that is, created for the use and functioning of the state) libraries and archives in Ancient Egypt throughout the dynastic period (c.3500−30 B.C.); their history, purpose and, to some extent, their administration. It also considers an aspect not explored in Sperry’s article, that of “private” libraries in Ancient Egypt (texts collected by an individual for their own personal use). Whilst estimated literacy levels within the general population precluded the widespread collection of texts for personal edification, there is evidence to suggest that private libraries were present in Ancient Egypt. The article concludes with a brief assessment of the legacy of these ancient libraries and their influence on the creation of the Library of Alexandria, in both its ancient and modern manifestations.

November 1994: CD-ROMs, Gopher: Freshman Research Habit; Archives Traveling Exhibit

Inside this Issue: Freshman ResearchScholarly CommunicationTraveling ExhibitActive PeopleIntroducing

February 2000: Advisory Board; Archives and Special Collections

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