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Magnetic record associated with tree ring density: possible climate proxy.

Kletetschka G, Pruner P, Venhodova D, Kadlec J - Geochem. Trans. (2007)

Bottom Line: A magnetic signature of tree rings was tested as a potential paleo-climatic indicator.Such a record suggests that the European LIA was a global phenomenon.Magnetic analysis of the thermal stability reveals the blocking temperatures near 200 degree C.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Geology, AS CR, Prague, 16502, Czech Republic. kletetschka@nasa.gov

ABSTRACT
A magnetic signature of tree rings was tested as a potential paleo-climatic indicator. We examined wood from sequoia tree, located in Mountain Home State Forest, California, whose tree ring record spans over the period 600 - 1700 A.D. We measured low and high-field magnetic susceptibility, the natural remanent magnetization (NRM), saturation isothermal remanent magnetization (SIRM), and stability against thermal and alternating field (AF) demagnetization. Magnetic investigation of the 200 mm long sequoia material suggests that magnetic efficiency of natural remanence may be a sensitive paleoclimate indicator because it is substantially higher (in average >1%) during the Medieval Warm Epoch (700-1300 A.D.) than during the Little Ice Age (1300-1850 A.D.) where it is <1%. Diamagnetic behavior has been noted to be prevalent in regions with higher tree ring density. The mineralogical nature of the remanence carrier was not directly detected but maghemite is suggested due to low coercivity and absence of Verwey transition. Tree ring density, along with the wood's magnetic remanence efficiency, records the Little Ice Age (LIA) well documented in Europe. Such a record suggests that the European LIA was a global phenomenon. Magnetic analysis of the thermal stability reveals the blocking temperatures near 200 degree C. This phenomenon suggests that the remanent component in this tree may be thermal in origin and was controlled by local thermal condition.

No MeSH data available.


Related in: MedlinePlus

Section of the tree sample that was used for magnetic measurements and tree ring density. Blue numbers indicate a year (AD) when the tree ring was created. Blue dots (pinpricks) help orientation in respect to individual tree ring ages. Each one dot is the 10th year, two vertical dots are the 50th year, three vertical dots are 100th year, and four vertical dots are the 1000th year.
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Figure 1: Section of the tree sample that was used for magnetic measurements and tree ring density. Blue numbers indicate a year (AD) when the tree ring was created. Blue dots (pinpricks) help orientation in respect to individual tree ring ages. Each one dot is the 10th year, two vertical dots are the 50th year, three vertical dots are 100th year, and four vertical dots are the 1000th year.

Mentions: A sample of the Sequoia sempervirens (m26 NE3–NE5) was obtained from professor Malcom Hughes on December 17, 1999, in the Laboratory of Tree-ring research, University of Arizona. The tree sample was collected in Mountain Home State Forest, California (SE of Fresno), and dated by Rex K. Adams. The specimen was cross-dated for the time interval between 950–1450 years. The rest of the years, estimated based on Figure 1, is not cross-dated and may be associated with some errors (+/-5 years). In Figure 1, one pinprick (blue dot) indicates the 10th year, two pinpricks in a vertical alignment indicate the 50th year, three pinpricks in a vertical alignment indicate the 100th year, and four pinpricks in a vertical alignment indicate the 1000th year.


Magnetic record associated with tree ring density: possible climate proxy.

Kletetschka G, Pruner P, Venhodova D, Kadlec J - Geochem. Trans. (2007)

Section of the tree sample that was used for magnetic measurements and tree ring density. Blue numbers indicate a year (AD) when the tree ring was created. Blue dots (pinpricks) help orientation in respect to individual tree ring ages. Each one dot is the 10th year, two vertical dots are the 50th year, three vertical dots are 100th year, and four vertical dots are the 1000th year.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1851700&req=5

Figure 1: Section of the tree sample that was used for magnetic measurements and tree ring density. Blue numbers indicate a year (AD) when the tree ring was created. Blue dots (pinpricks) help orientation in respect to individual tree ring ages. Each one dot is the 10th year, two vertical dots are the 50th year, three vertical dots are 100th year, and four vertical dots are the 1000th year.
Mentions: A sample of the Sequoia sempervirens (m26 NE3–NE5) was obtained from professor Malcom Hughes on December 17, 1999, in the Laboratory of Tree-ring research, University of Arizona. The tree sample was collected in Mountain Home State Forest, California (SE of Fresno), and dated by Rex K. Adams. The specimen was cross-dated for the time interval between 950–1450 years. The rest of the years, estimated based on Figure 1, is not cross-dated and may be associated with some errors (+/-5 years). In Figure 1, one pinprick (blue dot) indicates the 10th year, two pinpricks in a vertical alignment indicate the 50th year, three pinpricks in a vertical alignment indicate the 100th year, and four pinpricks in a vertical alignment indicate the 1000th year.

Bottom Line: A magnetic signature of tree rings was tested as a potential paleo-climatic indicator.Such a record suggests that the European LIA was a global phenomenon.Magnetic analysis of the thermal stability reveals the blocking temperatures near 200 degree C.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Geology, AS CR, Prague, 16502, Czech Republic. kletetschka@nasa.gov

ABSTRACT
A magnetic signature of tree rings was tested as a potential paleo-climatic indicator. We examined wood from sequoia tree, located in Mountain Home State Forest, California, whose tree ring record spans over the period 600 - 1700 A.D. We measured low and high-field magnetic susceptibility, the natural remanent magnetization (NRM), saturation isothermal remanent magnetization (SIRM), and stability against thermal and alternating field (AF) demagnetization. Magnetic investigation of the 200 mm long sequoia material suggests that magnetic efficiency of natural remanence may be a sensitive paleoclimate indicator because it is substantially higher (in average >1%) during the Medieval Warm Epoch (700-1300 A.D.) than during the Little Ice Age (1300-1850 A.D.) where it is <1%. Diamagnetic behavior has been noted to be prevalent in regions with higher tree ring density. The mineralogical nature of the remanence carrier was not directly detected but maghemite is suggested due to low coercivity and absence of Verwey transition. Tree ring density, along with the wood's magnetic remanence efficiency, records the Little Ice Age (LIA) well documented in Europe. Such a record suggests that the European LIA was a global phenomenon. Magnetic analysis of the thermal stability reveals the blocking temperatures near 200 degree C. This phenomenon suggests that the remanent component in this tree may be thermal in origin and was controlled by local thermal condition.

No MeSH data available.


Related in: MedlinePlus