Climate Variation and the Rise and Fall of an Andean Civilization

1997 ◽  
Vol 47 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Michael W. Binford ◽  
Alan L. Kolata ◽  
Mark Brenner ◽  
John W. Janusek ◽  
Matthew T. Seddon ◽  
...  
Keyword(s):  
Agricultural Production ◽  
Climate Changes ◽  
Drainage Basin ◽  
Sediment Cores ◽  
Agricultural Field ◽  
Lake Levels ◽  
Level Variation ◽  
Spatial And Temporal Patterns ◽  
Lake Titicaca ◽  
Basin Water

Paleolimnological and archaeological records that span 3500 years from Lake Titicaca and the surrounding Bolivian–Peruvian altiplano demonstrate that the emergence of agriculture (ca. 1500 B.C.) and the collapse of the Tiwanaku civilization (ca. A.D. 1100) coincided with periods of abrupt, profound climate change. The timing and magnitude of climate changes are inferred from stratigraphic evidence of lake-level variation recorded in14C-dated lake-sediment cores. Paleo-lake levels provide estimates of drainage basin water balance. Archaeological evidence establishes spatial and temporal patterns of agricultural field use and abandonment. Prior to 1500 B.C., aridity in the altiplano precluded intensive agriculture. During a wetter period from 1500 B.C. to A.D. 1100, the Tiwanaku civilization and its immediate predecessors developed specialized agricultural methods that stimulated population growth and sustained large human settlements. A prolonged drier period (ca. A.D. 1100–1400) caused declining agricultural production, field abandonment, and cultural collapse.

A 350014C yr High-Resolution Record of Water-Level Changes in Lake Titicaca, Bolivia/Peru

1997 ◽  
Vol 47 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Mark B. Abbott ◽  
Michael W. Binford ◽  
Mark Brenner ◽  
Kerry R. Kelts
Keyword(s):  
Water Level ◽  
Lake Level ◽  
Sediment Cores ◽  
Water Level Fluctuations ◽  
Lake Levels ◽  
Cultural Changes ◽  
Lake Titicaca ◽  
Water Level Rise ◽  
Andean Altiplano ◽  
Geochemical Analyses

Sediment cores collected from the southern basin of Lake Titicaca (Bolivia/Peru) on a transect from 4.6 m above overflow level to 15.1 m below overflow level are used to identify a new century-scale chronology of Holocene lake-level variations. The results indicate that lithologic and geochemical analyses on a transect of cores can be used to identify and date century-scale lake-level changes. Detailed sedimentary analyses of subfacies and radiocarbon dating were conducted on four representative cores. A chronology based on 60 accelerator mass spectrometer radiocarbon measurements constrains the timing of water-level fluctuations. Two methods were used to estimate the14C reservoir age. Both indicate that it has remained nearly constant at ∼25014C yr during the late Holocene. Core studies based on lithology and geochemistry establish the timing and magnitude of five periods of low lake level, implying negative moisture balance for the northern Andean altiplano over the last 3500 cal yr. Between 3500 and 3350 cal yr B.P., a transition from massive, inorganic-clay facies to laminated organic-matter-rich silts in each of the four cores signals a water-level rise after a prolonged mid-Holocene dry phase. Evidence of other significant low lake levels occurs 2900–2800, 2400–2200, 2000–1700, and 900–500 cal yr B.P. Several of the low lake levels coincided with cultural changes in the region, including the collapse of the Tiwanaku civilization.

Changes in the prairie–forest ecotone in northwest Ontario (Canada) across the Holocene

2021 ◽  
pp. 1-12
Author(s):  
Donya C. Danesh ◽  
Cale A.C. Gushulak ◽  
Melissa T. Moos ◽  
Moumita Karmakar ◽  
Brian F. Cumming
Keyword(s):  
Climate Changes ◽  
Transfer Functions ◽  
Sediment Cores ◽  
Lake Levels ◽  
Diatom Assemblages ◽  
Site Specific ◽  
The Holocene ◽  
Arboreal Pollen ◽  
Northwest Ontario ◽  
Forest Ecotone

Abstract Pollen and diatom assemblages from well-dated sediment cores from three lakes forming a west-to-east transect across the boreal forest in northwest Ontario (Canada) were used to evaluate the timing and nature of the movement of the prairie–forest ecotone (PFE) across the Holocene. Changes in vegetation, temperature, and effective moisture were inferred from pollen and pollen-based transfer functions. Analyses indicated site-specific vegetational and climate changes across short spatial distances, with prolonged prairie-like conditions during the middle Holocene at the westernmost site. Increased reconstructed temperatures at this westernmost site occurred from ~9000 to 3000 cal yr BP, alongside increases in diatom-inferred lake levels beginning at ~6000 cal yr BP. The abundance of Quercus peaked concurrently with rising lake levels before declining to trace levels by ~3000 cal yr BP. Increases in the abundance of non-arboreal pollen between ~8500 and ~4500 cal yr BP at the more eastern lakes suggest relatively delayed and truncated PFE influence, before the reestablishment of primarily boreal taxa by ~4500 cal yr BP, coincident with diatom-inferred increases in lake levels. This study shows that the PFE moved both farther east and north than previously determined, but generally agrees with established patterns in vegetation from other studied regions along the PFE.

Twelfth Century AD

2017 ◽  
Author(s):  
Lonnie G. Thompson ◽  
Alan L. Kolata
Keyword(s):  
Climate Change ◽  
Southern Oscillation ◽  
Sediment Cores ◽  
Critical Role ◽  
Lake Titicaca ◽  
Independent Evidence ◽  
Tropical Regions ◽  
Ice Cap ◽  
Paleoclimate Records ◽  
Past Climate Change

Climate is a fundamental and independent variable of human existence. Given that 50 percent of the Earth’s surface and much of its population exist between 30oN and 30oS, paleoenvironmental research in the Earth’s tropical regions is vital to our understanding of the world’s current and past climate change. Most of the solar energy that drives the climate system is absorbed in these regions. Paleoclimate records reveal that tropical processes, such as variations in the El Niño-Southern Oscillation (ENSO), have affected the climate over much of the planet. Climatic variations, particularly in precipitation and temperature, play a critical role in the adaptations of agrarian cultures located in zones of environmental sensitivity, such as those of the coastal deserts, highlands, and altiplano of the Andean region. Paleoclimate records from the Quelccaya ice cap (5670 masl) in highland Peru that extend back ~1800 years show good correlation between precipitation and the rise and fall of pre-Hispanic civilizations in western Peru and Bolivia. Sediment cores extracted from Lake Titicaca provide independent evidence of this correspondence with particular reference to the history of the pre-Hispanic Tiwanaku state centered in the Andean altiplano. Here we explore, in particular, the impacts of climate change on the development and ultimate dissolution of this altiplano state.

Antarctic Climate History and Global Climate Changes

2017 ◽  
Author(s):  
Pontus Lurcock ◽  
Fabio Florindo
Keyword(s):  
Ocean Circulation ◽  
Climate Changes ◽  
Numerical Models ◽  
Global Climate ◽  
Sediment Cores ◽  
Ice Sheets ◽  
Global Ocean ◽  
Climate History ◽  
Global Climate Changes ◽  
Planetary Albedo

Antarctic climate changes have been reconstructed from ice and sediment cores and numerical models (which also predict future changes). Major ice sheets first appeared 34 million years ago (Ma) and fluctuated throughout the Oligocene, with an overall cooling trend. Ice volume more than doubled at the Oligocene-Miocene boundary. Fluctuating Miocene temperatures peaked at 17–14 Ma, followed by dramatic cooling. Cooling continued through the Pliocene and Pleistocene, with another major glacial expansion at 3–2 Ma. Several interacting drivers control Antarctic climate. On timescales of 10,000–100,000 years, insolation varies with orbital cycles, causing periodic climate variations. Opening of Southern Ocean gateways produced a circumpolar current that thermally isolated Antarctica. Declining atmospheric CO2 triggered Cenozoic glaciation. Antarctic glaciations affect global climate by lowering sea level, intensifying atmospheric circulation, and increasing planetary albedo. Ice sheets interact with ocean water, forming water masses that play a key role in global ocean circulation.

scholarly journals Regional GRACE-based estimates of water mass variations over Australia: validation and interpretation

2013 ◽  
Vol 17 (12) ◽  
pp. 4925-4939 ◽  
Author(s):  
L. Seoane ◽  
G. Ramillien ◽  
F. Frappart ◽  
M. Leblanc
Keyword(s):  
Water Mass ◽  
Drainage Basin ◽  
Principal Component ◽  
Component Analysis ◽  
Climate Index ◽  
Accurate Estimation ◽  
Total Water ◽  
Spatial And Temporal Patterns ◽  
Regional Solutions

Abstract. Time series of regional 2° × 2° Gravity Recovery and Climate Experiment (GRACE) solutions have been computed from 2003 to 2011 with a 10-day resolution by using an energy integral method over Australia (112° E–156° E; 44° S–10° S). This approach uses the dynamical orbit analysis of GRACE Level 1 measurements, and specially accurate along-track K-band range rate (KBRR) residuals with a 1 μm s−1 level of errors, to estimate the total water mass over continental regions. The advantages of regional solutions are a significant reduction of GRACE aliasing errors (i.e. north–south stripes) providing a more accurate estimation of water mass balance for hydrological applications. In this paper, the validation of these regional solutions over Australia is presented, as well as their ability to describe water mass change as a response of climate forcings such as El Niño. Principal component analysis of GRACE-derived total water storage (TWS) maps shows spatial and temporal patterns that are consistent with independent data sets (e.g. rainfall, climate index and in situ observations). Regional TWS maps show higher spatial correlations with in situ water table measurements over Murray–Darling drainage basin (80–90%), and they offer a better localization of hydrological structures than classical GRACE global solutions (i.e. Level 2 Groupe de Recherche en Géodésie Spatiale (GRGS)) products and 400 km independent component analysis solutions as a linear combination of GRACE solutions provided by different centers.

scholarly journals Automated Quality Assessment of Crops Using CNN - Keras

2021 ◽  
pp. 641-645
Author(s):  
Meghashree ◽  
Alwyn Edison Mendonca ◽  
Ashika S Shetty
Keyword(s):  
Image Classification ◽  
Agricultural Production ◽  
Detection System ◽  
Cost Effective ◽  
Farming System ◽  
Modern Method ◽  
Innovative Technology ◽  
Disease Detection ◽  
Agricultural Field ◽  
Plant Leaf

Plant disease is an on-going challenge for the farmers and it has been one of the major threats to the income and the food security. This project is used to classify plant leaf into diseased and healthy leaf,to improve the quality and quantity of agricultural production in the country. The innovative technology that helps in improve the quality and quantity in the agricultural field is the smart farming system. It represented the modern method that provides cost-effective disease detection and deep learning with convolutional neural networks (CNNs) has achieved large successfulness in the categorisation of different plant leaf diseases. CNN reads a really very larger picture in a simple way. CNN nearly utilised to examine visual imagery and are frequently working behind the scenes in image classification. To extract the general features and then classify them under multiple based upon the features detected. This project will help the farmers financially in increasing the production of the crop yield as well as the overall agricultural production. The paper reviews the expected methods of plant leaf disease detection system that facilitates the advancement in agriculture. It includes various phases such as image preprocessing, image classification, feature extraction and detecting healthy or diseased.

Paleoclimatic reconstruction studies in lake sediments: major proxies, technical evolution and database

2020 ◽  
Author(s):  
Paula Bianchini ◽  
Elder Yokoyama ◽  
Luciana Prado
Keyword(s):  
Lake Sediments ◽  
Climate Changes ◽  
Environmental Changes ◽  
Drainage Basin ◽  
Spatial Scales ◽  
Temporal Variations ◽  
Quality Data ◽  
Anthropogenic Factors ◽  
Data Sets ◽  
Geochemical Composition

<p>Paleoclimate studies in different temporal and spatial scales provide important information on long-term statistics required to test hypotheses about climate changes. Comprehensive high-quality data sets and a solid understanding of dynamic climate processes in different temporal variations are essential to evaluate the sensitivity of the climatic system. Moreover, these data sets and dynamic analyses can help to distinguish the variability of natural and anthropogenic factors, reducing uncertainties about the magnitude and impact of future global climate changes. A common way to conduct paleoclimatic studies is through high resolution multiproxy lake sediments. Lake environments have been increasingly used in recent years to infer past fluctuations in climate, and many studies that comprise different locations and timescales demonstrate the great value of lakes as paleoclimatic archives. Because lake sediments are continental indicators sensitive to environmental changes, they can be used to reconstruct climate parameters, such as past rainfall, area management and environmental or limnological lake conditions. Changes of rainfall quantity can be recorded in lake archives by the variation of sedimentary input, which is related to changes in drainage basin and erosion rate. Beside of sedimentary input, lake sediments also exhibit physical and chemical changes in water bodies which, in turn, induce transformation in geochemical composition caused by changes in runoff or other allocated components. Thus, there is a variation in the proxies used in the studies, both in relation to the type of proxy used and the relationship used. In this context, we made a compilation of paleoclimatic studies on lake sediments (about 350 lakes), focusing on the main proxies used. Our study shows that there has been a change in the major proxies used along decades and with the emergence of new analysis techniques. In addition, we notice that lake characteristics (e.g., shape, geomorphological context, formation, etc.) have directly influence the proxies used and the quality of the information obtained. This compilation provides a database with an analysis of several lakes around the world, which can help future works and enable the identification of commonly used proxies according to the different variables that should be used, promoting more objective analyzes.</p>

scholarly journals Agriculture Adaptation to Consequences of Global Climate Changes

2021 ◽  
Vol 18 (2) ◽  
pp. 13-20
Author(s):  
D. G. Galkin
Keyword(s):  
Climate Change ◽  
Agricultural Production ◽  
Climate Changes ◽  
Greenhouse Gas Emission ◽  
Traditional Approach ◽  
Global Climate ◽  
Global Climate Changes ◽  
Change Impact ◽  
Agriculture Development

The goal of the article is to work out recommendations aimed at providing sustainability of agriculture development on the level of national economy in conditions of changing climate. The agriculture development within the frames of traditional approach can be studied in two aspects: as a sector subjected to the global climate change impact; as a sector promoting climate change due to greenhouse gas emission. The authors showed that in regard to present trends scientific recommendations aimed at agriculture adaptation to climate changes are the most significant for Russia. On the basis of provided concepts they identified key lines in the said adaptation: to develop innovation connected with adaptation to consequences of climate changes; to upgrade the system of agro-insurance; to use methods of organic food production; to monitor and appraise adaptation of agriculture to climate changes; to introduce strategic planning of sustainable development and location of agricultural production. These lines should be realized on the basis of integrity, strategic orientation and scientific support of agricultural production. These lines can stabilize the level of key parameters of the sector in the long-term perspective.

scholarly journals Revisit to Policy Formulation for Climate-Smart Agriculture in India

2019 ◽  
Vol 8 (9S2) ◽  
pp. 109-116
Keyword(s):  
Climate Change ◽  
Supply Chain ◽  
Food Security ◽  
Agricultural Production ◽  
Climate Changes ◽  
Agricultural Productivity ◽  
Small Scale ◽  
Farming Practices ◽  
Economic Implications ◽  
The Impact

Potential influence of water stress, climate change, erosion of fertility, unorganized agro-financing practices in agricultural-yields espoused with incongruity in regulating and developing the credible distribution mechanism for the resilience of computable equilibrium in the supply chain have warranted the continuing negative economic implications relating to agricultural production-patterns as well as ensuring food security of the country. An authoritative introspection for the sustainability of agro-economic policy in consistence with the increasing population becomes the cry of the hour of the country. Sensitivity-variance of different crops to warming though confines the scopes and preferences of territoriality of productivity however, the complexity of impact of climate-change on agricultural productivity necessitates the appraisal and interrelations of physical, economic and social factors as well changing ecological imbalances. The attempt to bring structural reforms in the farming practices in weather variability context in the country requires financial support for the marginal and small-scale farmers as farming practices are predominantly adapted to local climates. The global character of atmospheric circulation and the impact of ecological and climate-changes encourage combined use of climate, crop, and economic models for sustaining growth of supply chain to market. In addition, the increasing deterioration of agricultural production due to the eventuality of climate-change and eventual ecological imbalance considerably would affect the trade balance of the country for the legislative mandate of food security. To transform the progressive move of LPG (Liberalization, Privatization and Globalization) into secured and sustainable agro-economy to save our planet from the ravages of climate change, a comprehensive schematic approach involves configuration of legal and policy tools containing thereof: a) ‘spillover costs’ of agricultural productivity due to increased ecological and climate changes; b) coherent assessment of the modalities of agriculture to harmonize the present-day water-stressed; c) coherent financing mechanism for the farmers, in particular the small-scale and marginal ones who are not only being affected disproportionately rather the changes warrant them to be displaced internally. The present discussion reviews two prime factors: viz; a) Effects of Climate-Change upon agro-economy of the country; and b) Attenuation of Agro-financing measures in the regulatory mechanism for regulating and developing the vibrant supply chain to the market

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