Research conducted in various parts of the world indicates a rise in the activity of mass movements, including an increase in the number of landslides, in recent decades Innes, ; Winchester and Chaujar, ; Petley et al. The reason for this increase is greater precipitation, e. Attention is also paid to the growing population and increasing development of areas threatened by the occurrence of landslides Guzzetti et al. For example, on 23 July , in Kathmandu, very heavy rainfall caused a landslide of 9, m 3 , which turned into debris flow and floods, causing 16 human deaths Paudel et al. The increasing number of landslides and related economic losses have resulted in the development of new methods of mapping landslide activity, e. The use of landslide maps can limit the destruction of buildings and infrastructure, and the maps developed by means of the above-listed methods are used for rational-spatial planning Ives and Bovis, ; Bejar-Pizarro et al.
Dendrochronology – Tree Rings as Records of Climate Change
Welcome to dendrochronological www pages of the Department of Geosciences and Geography , University of Helsinki! Students aiming for dendrochronological thesis Bachelor, Master, Licentiate or Ph. Lecture course in Dendrochronology, , has been lectured at the Department of Geosciences and Geography , several times over the past years.
Dendrochronology was used to date objects and to extract further information between the dendrochronological date of the outermost ring and the painting.
Previous Next Contents. Dendrochronology is applied in cultural-heritage research including archaeology to determine the exact calendar age of ancient wood. Such age determinations contribute significantly to assessments of the meaning of archaeological and architectural structures in terms of their chronological and cultural context.
This method uses the fact that in climate zones with distinct growing seasons i. This seasonal rhythm is laid down in annual growth rings. The width of each ring reflects the environmental conditions during the growing season, such as temperature, precipitation and soil conditions, as well as local impacts such as flooding, fire and forest clearing or thinning. The alteration of wide and narrow growth rings in ancient wood provides a key to the exact period during which this wood was formed.
As an absolute dating method dendrochronology is restricted to the last 12, years Holocene , although the availability of reference chronologies means that in some regions dates are only possible for more recent time periods. Therefore it is essential that measurement series are deposited in trusted repositories and made available for follow-up research.
For a great deal of human history, wood has been an important construction material.
The Laboratory for Wood Anatomy and Dendrochronology
Dendrochronology , also called tree-ring dating , the scientific discipline concerned with dating and interpreting past events, particularly paleoclimates and climatic trends, based on the analysis of tree rings. Samples are obtained by means of an increment borer, a simple metal tube of small diameter that can be driven into a tree to get a core extending from bark to centre. This core is split in the laboratory, the rings are counted and measured, and the sequence of rings is correlated with sequences from other cores.
Dendrochronology is based on the fact that many species of trees produce growth rings during annual growing seasons. The width of the ring i.
1 Faculty of Science, Department of Physical Geography and Geoecology, Charles University in Prague, Albertov 6, Prague, , Czech Republic.
Moreover, it is still unclear whether large construction timbers, for use in Italy, came from the widespread temperate forests north of the Alps and were then transported to the sparsely-wooded Mediterranean region in the south. Here, we present dendrochronological results from the archaeological excavation of an expensively decorated portico in the centre of Rome. The oak trees Quercus sp. This rare dendrochronological evidence from the capital of the Roman Empire gives fresh impetus to the ongoing debate on the likelihood of transporting timber over long distances within and between Roman provinces.
This study reconstructs the administrative and logistic efforts required to transport high-quality construction timber from central Europe to Rome. It also highlights an advanced network of trade, and emphasises the enormous value of oak wood in Roman times. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: All relevant data are within the paper and Supporting Information files.
Dendrochronological dating of chests
Dendrochronology is the study of data from tree ring growth. Due to the sweeping and diverse applications of this data, specialists can come from many academic disciplines. There are no degrees in dendrochronology because though it is useful across the board, the method itself is fairly limited.
Dendrochronological dating of chests. Many chests in churches, cathedrals, abbeys and private collections are of great age, but many languish in damp.
In the present study, furniture and coopered vessels from three Austrian museums were examined. Dendrochronology was used to date objects and to extract further information such as the necessary time for seasoning, wood loss through wood-working and methods of construction. In most cases sampling was done by sanding the cross section and making digital photographs using a picture frame and measuring digitally. The dendrochronological dates of the sampled furniture range between and The group of furniture includes cupboards, chests, tables, benches, commodes and beds.
In many cases furniture was artfully painted and sometimes even shows a painted year. With the help of dendrochronology it was proved that some objects had been painted for some time after construction, or had been over-painted. Most furniture, however, was painted immediately after completion. In this case, the seasoning and storage time of the boards and the wood loss due to shaping can be verified.
As an average value, 14 years have passed between the dendrochronological date of the outermost ring and the painting. The time span includes time of seasoning and storage and the rings lost by wood-working. This leads, on the one hand to a short storage time of less than 10 years and on the other hand to very little wood loss due to manufacturing.
Those boards being less shaped turned out to be back panels of cupboards, therefore they are recommended to be sampled for dating. Coopered vessels were dated between and
Borgring Fortress Discovery: Dendrochronological Dating Results
Dendrochronology or tree-ring dating is the method by which timbers are precisely dated through measurement and analysis of the trees’ ring width.
Dendrochronology is the formal term for tree-ring dating, the science that uses the growth rings of trees as a detailed record of climatic change in a region, as well as a way to approximate the date of construction for wooden objects of many types. As archaeological dating techniques go, dendrochronology is extremely precise: if the growth rings in a wooden object are preserved and can be tied into an existing chronology, researchers can determine the precise calendar year—and often season—the tree was cut down to make it.
Radiocarbon dates which have been calibrated by comparison to dendrochronological records are designated by abbreviations such as cal BP, or calibrated years before the present. Tree-ring dating works because a tree grows larger—not just height but gains girth—in measurable rings each year in its lifetime. The rings are the cambium layer, a ring of cells that lies between the wood and bark and from which new bark and wood cells originate; each year a new cambium is created leaving the previous one in place.
How large the cambium’s cells grow in each year, measured as the width of each ring, depends on temperature and moisture—how warm or cool, dry or wet each year’s seasons were. At its most basic, during dry years the cambium’s cells are smaller and thus the layer is thinner than during wet years. Not all trees can be measured or used without additional analytical techniques: not all trees have cambiums that are created annually.
In tropical regions, for example, annual growth rings are not systematically formed, or growth rings are not tied to years, or there are no rings at all. Evergreen cambiums are commonly irregular and not formed annually. Trees in arctic, sub-arctic and alpine regions respond differently depending on how old the tree is—older trees have reduced water efficiency which results in a reduced response to temperature changes. Tree-ring dating was one of the first absolute dating methods developed for archaeology, and it was invented by astronomer Andrew Ellicott Douglass and archaeologist Clark Wissler in the first decades of the 20th century.
By comparing the pattern of wide and narrow rings from a timber of unknown age with tree-ring chronologies from Northern Europe, the precise chronological position of the measured tree-ring series from the timber can be found. As the position of these chronologies is precisely dated by linking them with tree-ring data from living trees, an accurate date for the timber can be given.
If bark or bark edge is preserved on the sample or object, the dating for the felling of the tree is accurately dated.
The article presents the results of dating the Staroturukhansk fortified settlement – a monument from the time of the Russian colonization of Siberia, and briefly.
The focus of the laboratory is on dendrochronological age determination of wood material from archaeological excavations, historical constructions, ship wrecks, art work etc. All material sent to the laboratory is registered and archived, and the laboratory hosts the by far most extensive and regularly updated collection of reference series for dendrochronological dating in Sweden.
Dating with yearly precision is commonly possible back to about year before the present, sometimes considerably earlier than that, and in some cases it is even possible to determine during which season of the year the tree was felled. Even much older material can be dated with very high precision through combination with radiocarbon dating. In many cases the geographical origin provenance of wooden artefacts can also be determined. Wood anatomical analyses of small samples, such as charcoal fragments, are also performed at the laboratory, and microscopic analyses for species determination can be combined with age determination at the radiocarbon dating laboratory , which is also hosted by the Department of Geology.
Hence, age and provenance determination can be applied to many different types of artefacts, deposits and constructions that contain wooden materials, information of great importance within a variety of disciplines, such as geology, archaeology, history and arts. Palaeoclimate research based on tree-ring series dendroclimatology is also carried out at the laboratory.
This type of studies can be based on living trees, historical construction timber or wood remains preserved in lakes or peat deposits. Variations in temperature, moisture and a number of other environmental properties may be recorded as changes in ring width but also, for example, as changes in the stable carbon- and oxygen-isotope composition of wood samples. This type of palaeoclimate research, which is commonly carried out as part of PhD student projects, is integrated with research in Quaternary Sciences at the Department of Geology, and a recent example is given by Johannes Edvardsson’s PhD thesis.
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Dendrochronology: What Tree Rings Tell Us About Past and Present
All rights reserved. Archaeologists use dendrochronology to date a shipwreck found off the coast of Germany. Archaeologists have a group of unlikely allies: trees. Dendrochronology, the scientific method of studying tree rings, can pinpoint the age of archaeological sites using information stored inside old wood. Originally developed for climate science, the method is now an invaluable tool for archaeologists, who can track up to 13, years of history using tree ring chronologies for over 4, sites on six continents.
Under ideal conditions, trees grow quickly, leaving wide annual rings behind.
Journal article. Access the full text Link. Lookup at Google Scholar. We are reporting the first dendrochronological dating of timber from Tajikistan. Thirty samples were collected from two old buildings from a village located in the western Pamir-Alay; eight cores were taken from temple. Most of the construction wood was juniper species. The object chronologies crossdated well with the previously published chronology based on living juniper trees from western Pamir-Alay.
The results of dating revealed that investigated structures are composed of wood coming from several periods. Besides dating of the wood samples from these historic structures, our investigation provides the opportunity to extend the currently existing regional tree-ring chronology for future climate reconstruction of the Pamir-Alay and High Asia. Dated sequences were assembled into a year chronology spanning the period — C.
The study of climate changes and past events by comparing the successive annual growth rings of trees or old timber. The study of annual rings in trees in order to analyze past climate conditions or to determine the date of past events. Trees grow more slowly in periods of drought or other environmental stress than they do under more favorable conditions, and thus the annual rings they produce are smaller.
Dating of archaeological timbers. Dating of period buildings. Dendrochronology or tree-ring dating is the scientific method of dating using the annual nature of tree growth in suitable tree species. Dendrochronology allows the exact calendar year in which each tree rings was formed to be established enabling the precise dating of trees and timbers. Five reasons to choose Tree-Ring Services:. We undertake both private and commercial commissions in dendrochronology throughout the UK:.
Waxham Barn — Norfolk. Parham House — W Sussex.
Dendrochronology: How Tree-Ring Dating Reveals Human Roots
Absolute dating of mass movements is crucial for disentangling possible release factors and determining the frequency of events. Here, we present an overview of a recent approach to dendrochronological dating of rockfalls, flows, landslides and avalanches. The results, based on 69 casestudies, show that methodological approaches to sampling and material processing differ considerably for different types of mass movements.
Landslides are usually detected through abrupt growth changes and changes in stem eccentricity, whereas high-energy events as avalanches and flows are mostly identified by the formation of traumatic resin ducts, reaction wood, growth injuries and eccentricity changes.
Subsequent to cross-dating, tree-ring chronology becomes dated with absolute accuracy. Climatic and environmental factors influence the growth of tree-rings.
Dendrochronology, an analysis of tree rings, is a commonly used method for dating wooden structures in archaeological remains and historical objects. Fascinating subjects of examination are the historical oil paintings on oak panels. Here, we applied a tree ring analysis on three boards of a Dutch painting from the Sinebrychoff Art Museum Helsinki.
Tree rings were measured using the conventional lens-assisted method, in addition to the photography-based approach, where the widths of the rings were determined from digital enlargements of the photos. These two methods produced comparable tree ring series. The lens- and photography-based records of the measured panel exhibited higher agreement with each other than the conventional, lens-based, record against the different master chronologies.