Geomorphological Development of the Memphite Floodplain Over the Past 6,000 Years

2013 ◽  
Vol 30 (2) ◽  
pp. 61-67 ◽  
Author(s):  
Judith Bunbury
Keyword(s):  
Landscape Change ◽  
Ice Age ◽  
Landscape Changes ◽  
River Systems ◽  
The Past ◽  
Landscape Processes ◽  
Northern Egypt ◽  
Last Ice Age ◽  
River Migration

Abstract The Memphite ruin mounds around the modern town of Mit Rahina in northern Egypt form a part of a region around which the capital of Egypt mi grated through time. Some of these migrations were the responses to landscape changes and the area is one that is subject to a number of types of landscape change. The delta and river systems as well as the deserts that surround Memphis changed profoundly as global temperatures rose at theend of the last ice age. This paper summarises the main landscape processes that affected the area and pro poses a model for river migration and delta-head change in the Memphite floodplain.

Vegetation disturbance and human population in Colombia – a regional reconstruction

Antiquity ◽  
2004 ◽  
Vol 78 (302) ◽  
pp. 828-838 ◽  
Author(s):  
Robert Marchant ◽  
Hermann Behling ◽  
Juan Carlos Berrio ◽  
Henry Hooghiemstra ◽  
Bas van Geel ◽  
...  
Keyword(s):  
Human Activities ◽  
Human Population ◽  
Ice Age ◽  
Pollen Record ◽  
Landscape Changes ◽  
The Andes ◽  
Vegetation Disturbance ◽  
The People ◽  
Regional Reconstruction ◽  
Last Ice Age

Palaeoecologists using pollen to map vegetation since the last ice age have noted numerous changes – which they feel increasingly obliged to blame on humans. These changes, such as deforestation or the dominance of certain plants, may happen suddenly or take place over thousands of years. The authors study the pollen record in Colombia, identify plants diagnostic of cultivation or disturbed ground (“degraded vegetation”) and use them to map human activities by proxy. They show how the people move and the landscape changes between 5000 BP and the present day, from the coast inland, and from the lowlands up into the Andes.

scholarly journals Landscape Change in Mediterranean Farmlands: Impacts of Land Abandonment on Cultivation Terraces in Portofino (Italy) and Lesvos (Greece)

2014 ◽  
Vol 7 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Theo Van Der Sluis ◽  
Thanasis Kizos ◽  
Bas Pedroli
Keyword(s):  
Land Use ◽  
Landscape Change ◽  
Agricultural Land ◽  
Urban Expansion ◽  
Population Decline ◽  
Aerial Photographs ◽  
Landscape Changes ◽  
The Past ◽  
Mediterranean Landscapes ◽  
The Mediterranean

Abstract The Mediterranean landscape has been rapidly changing over the past decades. Many regions saw a population decline, which resulted in changing land use, abandonment of marginal lands and colonisation by shrubs and tree species. Typical features like farming terraces, olive yards, and upland grasslands have been decreasing over the past 50 years. This results in a declining biodiversity and loss of traditional Mediterranean landscapes. In this paper we assess the landscape changes that took place in two areas, in Portofino, on the Italian Riviera, and Lesvos, a Greek island near the Turkish coast. We compared land use maps and aerial photographs over the past decades to quantify the land use changes in these two areas. Additional information was acquired from farmers’ interviews and literature. We found that changes are related to societal changes in the appraisal of agricultural land uses, and to the urban expansion, tourism and recreation. These diffuse processes are a result of policy measures and autonomous societal transformations. This is confirmed by the results of two interview surveys: between 1999 and 2012 agricultural land use in Portofino regional Park and buffer zone further marginalised, and the associated landscape changes are perceived as a substantial loss of character and identity. This problem is emblematic for large parts of the Mediterranean. Comparing different landscapes reveal similar processes of landscape change, which can be related to similar driving forces. Based on such comparisons, we learn about possible trajectories of change, and ask for a comprehensive approach to land use management.

scholarly journals In Anticipation of Extirpation

2020 ◽  
Vol 12 (1) ◽  
pp. 113-131 ◽  
Author(s):  
Patrick D. Nunn
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Ice Age ◽  
Optimal Solutions ◽  
The Holocene ◽  
The Past ◽  
Coastal Cities ◽  
The People ◽  
Northwest Europe ◽  
Last Ice Age

Abstract As concern about sea level rise grows and optimal solutions are sought to address its causes and effects, little attention has been given to past analogs. This article argues that valuable insights into contemporary discussions about future sea level rise can be gained from understanding those of the past, specifically the ways in which coastal peoples and societies reacted during the period of postglacial sea level rise. For much of the Holocene, most continental people eschewed coastal living in favor of inland areas. In many places large coastal settlements appeared only after the development of polities and associated crosswater networks. Postglacial sea level rise affected coastal living in ways about which we remain largely ignorant. Yet, millennia-old stories from Australia and northwest Europe show how people responded, from which we can plausibly infer their motivations. Stories from Australia say the people have succeeded in halting sea level rise, whereas those from northwest Europe indicate that people have failed, leading to the drowning of coastal cities such as Ys (Brittany) and Cantre’r Gwaelod (Wales). This distinction is explained by the contrasting duration of postglacial sea level rise in these regions; around Australia, sea level stopped rising 7,000 years ago, while along many coasts of northwest Europe it has risen unceasingly since the last ice age ended. The nature of past human and societal responses to postglacial sea level rise holds important insights for the future.

Possible pathways to a Dansgaard-Oeschger (DO) PMIP protocol

2021 ◽  
Author(s):  
Irene Malmierca-Vallet ◽  
Louise C. Sime ◽  
Paul J. Valdes
Keyword(s):  
General Circulation ◽  
Climate Changes ◽  
General Circulation Models ◽  
Ice Age ◽  
Climate Change Projections ◽  
The Past ◽  
External Perturbations ◽  
Mis 3 ◽  
Last Ice Age ◽  
Earth System Models

<p>The DO events of the last ice age represent one of the best studied abrupt climate transitions, yet we still lack a comprehensive explanation for them. There is uncertainty whether current IPCC-relevant models can effectively represent the processes that cause DO events. Current Earth system models (ESMs) seem overly stable against external perturbations and incapable of reproducing most abrupt climate changes of the past (Valdes, 2011). If this holds true, this could noticeably influence their capability to predict future abrupt transitions, with significant consequences for the delivery of precise climate change projections.  In this task, the objectives of this study are (1) to cross compare existing simulations that show spontaneous DO-type oscillations using a common set of diagnostics so we can compare the mechanisms and the characteristics of the oscillations, and (2) to formulate possible pathways to a DO PMIP protocol that could help investigate cold-period instabilities through a range of insolation-, freshwater-, GHG-, and NH ice sheet-related forcings, as well as evaluating the possibility of spontaneous internal oscillations.</p><p>Although most abrupt DO events happened during MIS3, only few studies investigate DO events in coupled general circulation models under MIS 3 conditions (e.g., Kawamura et al., 2017; Zhang and Prange, 2020). Here, we thus propose that the MIS3 period could be the focus of such a DO-event modelling protocol. More specific sensitivity experiments performed under MIS 3 boundary conditions are needed in order to (1) better understand the mechanisms behind millennial-scale climate variability, (2) explore AMOC variability under intermediate glacial conditions, and (3) help answer the question: “are models too stable?”.</p>

Fluvialism or diluvialism? Changing views on superfloods and landscape change

1994 ◽  
Vol 18 (3) ◽  
pp. 335-342 ◽  
Author(s):  
R.J. Huggett
Keyword(s):  
Landscape Change ◽  
Continental Margins ◽  
Landscape Changes ◽  
Drainage Systems ◽  
Landscape Features ◽  
The Past ◽  
Growing Body ◽  
Asteroids And Comets

In a series of recent articles, the possibility was raised that, owing to the occasional impact of asteroids and comets in the oceans, lowlands on continental margins might be prone to superflooding (Huggett, 1988a; 1988b; 1989a). It was suggested that a number of landscape features, including diverted drainage systems, gorges, valley meanders and extensive sheets of gravel might have been created by these superfloods. At the conclusion of the 1989 article it was noted that many landscape changes that might be ascribed to the action of superwaves are the same as the landscape changes accredited to the Noachian Deluge by the old school of diluvialists led at its zenith in the 1820s by William Buckland (see Huggett, 1989b). Thus, the bombardment hypothesis, through its prediction of superwaves and superfloods, leads to a new brand of diluvialism. This article explores the nature of neodiluvialism a little further, drawing attention to a growing body of evidence suggesting that, owing to various agencies, truly catastrophic floods have occurred in the past. It also discusses landscape features which can be expected to have been fashioned by diluvial, rather than by fluvial, action.

scholarly journals Plankton, from the last ice age to the year 3007

2008 ◽  
Vol 65 (3) ◽  
pp. 296-301 ◽  
Author(s):  
E. C. Pielou
Keyword(s):  
Positive Feedback ◽  
Climate Changes ◽  
Thermohaline Circulation ◽  
Canadian Arctic ◽  
Ice Age ◽  
Climate Forcing ◽  
The Arctic ◽  
Mackenzie Delta ◽  
The Past ◽  
Last Ice Age

Abstract Pielou, E. C. 2008. Plankton, from the last ice age to the year 3007. – ICES Journal of Marine Science, 65: 296–301. Climate forcing of the environment and biota has been happening since time immemorial, human forcing only for the past 200 years or so. This paper considers, first, climatic changes over the past 30 000 years, as indicated by plankton and their effects on plankton. Only fossilizable plankton can be observed: principally foraminifera, radiolaria, and pteropods in the zooplankton, and their food, principally coccolithophores, diatoms, and dinoflagellate cysts, in the phytoplankton. The soft-bodied zooplankton species—especially copepods—that lived with them can only be inferred. Large, abrupt climate changes took place, aided by positive feedback. Second, this paper attempts to predict how human forcing in the form of anthropogenic climate change is likely to affect marine ecosystems in the future. Past predictions have underestimated the speed at which warming is actually happening: positive feedback has been unexpectedly strong. Thus, the melting of snow and ice, by reducing the earth's albedo, has increased the amount of solar energy absorbed. Also, warming of the surface (water and land) has caused outgassing of methane from buried clathrates (hydrates), and methane is a strong greenhouse gas. Currently, predictions emphasize one or the other of two contrasted alternatives: abrupt cooling caused by a shutdown of the thermohaline circulation (the “ocean conveyor”) or abrupt warming caused by copious outgassing of methane. Both arguments (the former from oceanographers and the latter from geophysicists) are equally persuasive, and I have chosen to explore the methane alternative, because I am familiar with an area (the Beaufort Sea and Mackenzie Delta) where outgassing has recently (2007) been detected and is happening now: in the Arctic Ocean and the Canadian Arctic Archipelago, where disappearance of the ice will affect currents, temperature, thermocline, salinity, upwelling, and nutrients, with consequent effects on the zooplankton.

Canadians and their forest: Development of the National Forest Strategy

2003 ◽  
Vol 79 (4) ◽  
pp. 757-760
Author(s):  
T M. (Mike) Apsey
Keyword(s):  
Forest Management ◽  
Key Words ◽  
Policy Development ◽  
Sustainable Forest Management ◽  
Forest History ◽  
Ice Age ◽  
Aboriginal Peoples ◽  
National Forest ◽  
The Past ◽  
Last Ice Age

Canada's forest has evolved since the retreat of the last ice age, over a period of about 10 000 years. The forest has been modified by humans over much of this time, beginning with Aboriginal peoples' use of fire. Since the arrival of European colonists in the 16th century, use of the forest has been based on a changing series of policies and practices, leaving 94% of the original forest. Over the past 25 years, extensive public processes have led to a series of national forest strategies, each reflecting the evolving importance that Canadians hold for their forest. Key words: forest history, policy development, national forest strategy, Canada Forest Accord, sustained yield, sustainable forest management.

scholarly journals Subglacial floods beneath ice sheets

2006 ◽  
Vol 364 (1844) ◽  
pp. 1769-1794 ◽  
Author(s):  
G.W Evatt ◽  
A.C Fowler ◽  
C.D Clark ◽  
N.R.J Hulton
Keyword(s):  
Ice Sheets ◽  
Ice Sheet ◽  
Ice Age ◽  
Laurentide Ice Sheet ◽  
Ice Caps ◽  
The Past ◽  
Last Ice Age ◽  
Climatic Disturbances ◽  
Time Periodic ◽  
Do So

Subglacial floods (jökulhlaups) are well documented as occurring beneath present day glaciers and ice caps. In addition, it is known that massive floods have occurred from ice-dammed lakes proximal to the Laurentide ice sheet during the last ice age, and it has been suggested that at least one such flood below the waning ice sheet was responsible for a dramatic cooling event some 8000 years ago. We propose that drainage of lakes from beneath ice sheets will generally occur in a time-periodic fashion, and that such floods can be of severe magnitude. Such hydraulic eruptions are likely to have caused severe climatic disturbances in the past, and may well do so in the future.

scholarly journals Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age

2021 ◽  
Author(s):  
Jesse R. Farmer ◽  
Daniel M. Sigman ◽  
Julie Granger ◽  
Ona M. Underwood ◽  
François Fripiat ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Surface Waters ◽  
Ice Age ◽  
The Arctic ◽  
Bering Strait ◽  
Central Arctic Ocean ◽  
Phytoplankton Productivity ◽  
Nitrate Consumption ◽  
Western Arctic ◽  
Last Ice Age

AbstractSalinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sediments since 35,000 years ago to reconstruct past changes in nutrient sources and the degree of nutrient consumption in surface waters, the latter reflecting stratification. During the last ice age and early deglaciation, the Arctic was dominated by Atlantic-sourced nitrate and incomplete nitrate consumption, indicating weaker stratification. Starting at 11,000 years ago in the western Arctic, there is a clear isotopic signal of Pacific-sourced nitrate and complete nitrate consumption associated with the flooding of the Bering Strait. These changes reveal that the strong stratification of the western Arctic relies on low-salinity inflow through the Bering Strait. In the central Arctic, nitrate consumption was complete during the early Holocene, then declined after 5,000 years ago as summer insolation decreased. This sequence suggests that precipitation and riverine freshwater fluxes control the stratification of the central Arctic Ocean. Based on these findings, ongoing warming will cause strong stratification to expand into the central Arctic, slowing the nutrient supply to surface waters and thus limiting future phytoplankton productivity.

scholarly journals Latin America in Global History: An Historiographic Overview

2017 ◽  
Vol 30 (60) ◽  
pp. 253-272 ◽  
Author(s):  
Diego Olstein
Keyword(s):  
Latin America ◽  
Sixteenth Century ◽  
New World ◽  
World History ◽  
The Other ◽  
Ice Age ◽  
Global History ◽  
The World ◽  
Last Ice Age ◽  
Great Divergence

Abstract World history can be arranged into three major regional divergences: the 'Greatest Divergence' starting at the end of the last Ice Age (ca. 15,000 years ago) and isolating the Old and the New Worlds from one another till 1500; the 'Great Divergence' bifurcating the paths of Europe and Afro-Asia since 1500; and the 'American Divergence' which divided the fortunes of New World societies from 1500 onwards. Accordingly, all world regions have confronted two divergences: one disassociating the fates of the Old and New Worlds, and the other within either the Old or the New World. Latin America is in the uneasy position that in both divergences it ended up on the 'losing side.' As a result, a contentious historiography of Latin America evolved from the very moment that it was incorporated into the wider world. Three basic attitudes toward the place of Latin America in global history have since emerged and developed: admiration for the major impact that the emergence on Latin America on the world scene imprinted on global history; hostility and disdain over Latin America since it entered the world scene; direct rejection of and head on confrontation in reaction the former. This paper examines each of these three attitudes in five periods: the 'long sixteenth century' (1492-1650); the 'age of crisis' (1650-1780); 'the long nineteenth century' (1780-1914); 'the short twentieth century' (1914-1991); and 'contemporary globalization' (1991 onwards).

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