Complex weathering in drylands: implications of 'stress' history for rock debris breakdown and sediment release

Weathering studies have often sought to explain features in terms of a prevailing set of environmental conditions. However, it is clear that in most present-day hot desert regions, the surface rock debris has been exposed to a range of weathering environments and processes. These different weathering conditions can arise in two ways, either from the effects of long-term climate change acting on debris that remains relatively static within the landscape or through the spatial relocation of debris from high to low altitude. Consequently, each fragment of rock may contain a unique weathering-related legacy of damage and alteration — a legacy that may greatly influence its response to present-day weathering activity. Experiments are described in which blocks of limestone, sandstone, granite and basalt are given ‘stress histories’ by subjecting them to varying numbers of heating and freezing cycles as a form of pre-treatment. These imposed stress histories act as proxies for a weathering history. Some blocks were used in a laboratory salt weathering simulation study while others underwent a 2 year field exposure trial at high, mid and low altitude sites in Death Valley, California. Weight loss and ultrasonic pulse velocity measurements suggest that blocks with stress histories deteriorate more rapidly than unstressed samples of the same rock type exposed to the same environmental conditions. Laboratory data also indicate that the result of imposing a known ‘weathering history’ on samples by pre-stressing them is an increase in the amount of fine sediment released during salt weathering over a given period of time in comparison to unstressed samples.

Greek-Turkish Dilemmas and the Cyprus-EU Accession Process

This article compares the processes of foreign policymaking in Greece and Turkey in order to examine why the incentives and pressures of the enlargement process have failed until now to initiate a settlement in the Cyprus bicommunal negotiations. While most studies on the Cyprus problem have focused on the two communities of the island, little at-tention has been paid to the policies of the two â??motherlandsâ??, namely Greece and Turkey. Yet their leverage on the two Cypriot communities and their conflicting expectations with regard to an enlarged Europe in the Eastern Mediterranean constitute a complex security puzzle. The Republic of Cyprus stands as a champion candidate member for the next enlargement, amid fears of Turkish reprisals and hopes for a po-litical settlement on the island. With the benefits of settlement overwhelming the benefits of any other alternative, it is paradoxical that the parties seem to be about to fail to reach a last-minute, mutually beneficial compromise. I try to resolve this paradox by supplementing rational choice theory with cognitivist theories of international relations. While rational choice predicts a direct relationship between external environment and foreign policy shifts, the case of Cyprus suggests that this relationship is actually indirect. Without understanding how the external environment is framed in the domestic political discourse of Greece and Turkey, it is impossible to demonstrate how outside pressure and incentives affect foreign policy shifts.

Genealogies of Partition: History, History-Writing and 'The Troubles' in Ireland

Contemporary political disputes have a long history of expression and contestation through the genre of history-writing in Ireland. The role of history writing and political science writing during the nearly 40 years of the so-called 'Troubles' has been no exception to this. Battles between competing versions of what the conflict 'is about', mediated through academic and popular texts have themselves in turn become constitutive of it. This builds upon centuries of the representation of the complicated politics of this island as 'an issue' in British domestic politics - first 'the Catholic question', then 'the Irish question'. The location of political power outside the island for centuries has created successive battles for the representation of sectional interests in a metropolitan centre. The skills of propaganda, history writing, newspaper writing have consequently been deployed at a remarkable level of skill and intensity. In the recent period one of the consequences of this has been the removal from the debate of the actuality of partition; this builds upon a particular historical representation of partition as an historical inevitability. To seek to restore partition to the debate is not to call for its undoing but to recognise that seeking to circumvent debates about its origins in the key period of democratisation in Irish politics (1880-1920) has been counter-productive. This essay examines the genealogies of partition in Irish and international contexts in the light of these battles for representation, and aims to return a lost dimension to the debate about the so-called 'Troubles'in Ireland. The genealogy of partition is the issue that has been marginalised in academic study and this has affected both policy and politics.

'Ancient Enmities' and Modern Conflict: History and Politics in Northern Ireland

This article investigates the role of history and historical consciousness in deeply divided societies. It looks at the case of Northern Ireland. It argues that, while the conflict here is caused by contemporary divisions, perceptions of the past have had considerable influence. Recent years have seen efforts to change historical attitudes and this has aided political accommodation. An important lesson from the conflict in Northern Ireland points to the need to challenge such historical perceptions.