Search results for "chronology"
showing 10 items of 338 documents
Estrazione e raffinazione dello zolfo e paesaggio nella Sicilia romana tra IV e VI d.C.
2016
Sulphur was important in several fields: military, tanning, wool’s disinfection and many other activities. Nevertheless, the largest quantity of sulphur was used in agriculture, particularly in viticulture as it was used to combat fungal diseases especially in wine production areas. Sicily, and in particular the area surrounding Agrigento, was the main site of sulphur extraction. This built strong relationships with Rome and other agricultural centres in the Mediterranean Sea. Very important among the historical sources and the archaeological evidence are the so called Tabulae sulphuris, concerning the sulphur exploitation at the Agrigento’s area. Recent finds and studies gave a new chronol…
Revising midlatitude summer temperatures back to A.D. 600 based on a wood density network
2015
Annually resolved and millennium-long reconstructions of large-scale temperature variability are primarily composed of tree ring width (TRW) chronologies. Changes in ring width, however, have recently been shown to bias the ratio between low- and high-frequency signals. To overcome limitations in capturing the full spectrum of past temperature variability, we present a network of 15 maximum latewood density (MXD) chronologies distributed across the Northern Hemisphere extratropics. Independent subsets of continental-scale records consistently reveal high MXD before 1580 and after 1910, with below average values between these periods. Reconstructed extratropical summer temperatures reflect n…
De Habsburgos a Borbones. Legistas y canonistas en la Real Universidad de México
2020
A lo largo de todo el periodo colonial, la Universidad de México fue mayoritariamente canonista en cuanto a las preferencias de sus estudiantes juristas. Sin embargo, hemos podido comprobar que para el tránsito de los siglos XVII a XVIII se aprecia alguna diferencia o particularidad, en cuanto que, respecto a algunos parámetros, las referencias sobre Leyes llegan a superar a las de Cánones. La cronología de esta singularidad resulta coincidente con los cambios en la política de nombramiento de las autoridades novohispanas, especialmente para la Audiencia. En este estudio intentamos acercarnos a la relación explicativa que pudiera haber entre estas dos realidades, cuestionándonos algunas pos…
A global perspective on the climate‐driven growth synchrony of neighbouring trees
2020
2 .pdf files: File 1. Author's article final version, Post-Print (19 Pags.- 4 Figs.- 2 Tabls.). File 2. Supplementary Materials (3 Figs.- 2 Tabls.- 1 Model Equation).
New Tree-Ring Evidence from the Pyrenees Reveals Western Mediterranean Climate Variability since Medieval Times
2017
Paleoclimatic evidence is necessary to place the current warming and drying of the western Mediterranean basin in a long-term perspective of natural climate variability. Annually resolved and absolutely dated temperature proxies south of the European Alps that extend back into medieval times are, however, mainly limited to measurements of maximum latewood density (MXD) from high-elevation conifers. Here, the authors present the world’s best replicated MXD site chronology of 414 living and relict Pinus uncinata trees found >2200 m above mean sea level (MSL) in the Spanish central Pyrenees. This composite record correlates significantly ( p ≤ 0.01) with May–June and August–September mean …
Using machine learning on tree-ring data to determine the geographical provenance of historical construction timbers
2023
Funder: Bavarian Climate Research Network (BayKliF)
Les Campaniformes dans le sud-est de la France
2004
The term "Bell Beaker", in the strict sense, designates a ceramic beaker form with an S-shaped profile that gives it the shape of an inverted bell. This type of drinking-vessel is characterized by both its very particular pattern of decoration and by the generally skilled execution of that decoration. By extension, the decoration characteristic of these beakers bas allowed the expansion of the category "Bell-Beaker" to include other pottery forms and even other types of decoration showing the same tradition, vvhich probably represent an evolution or reproduction of the original Bell Beaker pattern, The recognition of these objects and their definition as a class date to the nineteenth centu…
Long-term decrease in Asian monsoon rainfall and abrupt climate change events over the past 6,700 years
2021
Significance The variability of the Asian summer monsoon (ASM) is important for the functioning of ecological and societal systems at regional to continental scales, but the long-term evolution and interannual variability of this system is not well understood. Here, we present a stable isotope–based reconstruction of ASM variability covering 4680 BCE to 2011 CE. Superimposed on a gradual drying trend, a rapid drop in mean annual precipitation (>40%) toward persistently drier conditions occurred in ∼1675 BCE. This megadrought caused regional forest deterioration and enhanced aeolian activity affecting Chinese ecosystems. We argue that this abrupt aridification starting ∼2000 BCE triggered wa…
Using growth and geochemical composition of Clathromorphum compactum to track multiscale North Atlantic hydro-climate variability
2020
International audience; Records of ocean/atmosphere dynamics over the past centuries are essential to understand processes driving climate variability. This is particularly true for the Northwest Atlantic which is a key region with an essential role in global climate regulation. Over the past two decades, coralline red algae have been increasingly used as environmental and climatic archives for the marine realm and hold the potential to extend long-term instrumental measurements. Here, we investigate the possibility to extract climate and environmental information from annual growth patterns and geochemical composition of the coralline red algae, Clathromorphum compactum, from Saint-Pierre …
Signals and memory in tree-ring width and density data
2015
It has been suggested that maximum latewood density (MXD) should be used instead of tree-ring width (TRW) data to reconstruct post-volcanic cooling effects. A thorough assessment of high frequency signals and potentially differing memory effects in long MXD and TRW chronologies, in response to large volcanic eruptions, is still missing, however. We here present a compilation of MXD and TRW chronologies from 11 sites in the Northern Hemisphere, covering the past 750+ years, and containing significant June–August temperature signals. Basic assessment of the data using Superposed Epoch Analysis reveals a temporally extended response in TRW, by 2–3 years, to large volcanic eruptions, though pos…