Assessing geomagnetic signal attenuation in North Atlantic deep-sea paleomagnetic records

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Author(s): Strano, S. E.; Stoner, J. S.; Xuan, C.
Author Affiliation(s): Primary:
Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, OR, United States
Volume Title: AGU 2012 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2012; American Geophysical Union 2012 fall meeting, San Francisco, CA, Dec. 3-7, 2012. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Deep-sea sediments, particularly those from the North Atlantic, have been instrumental in the development of modern paleomagnetic concepts. However, there is evident signal attenuation when compared with ultra-high resolution or archeomagnetic records from the same region and time interval. We assess this smoothing by using seven high-resolution (∼10-65 cm/kyr) deep-sea sediment cores taken from the western (KN158-04-2GC, KN158-04-22GC and IODP Site U1305) and eastern North Atlantic (KN158-04-53GC, KN158-04-46GC, KN158-04-57GC and ODP Site 984). We compare these independently dated and high-quality paleomagnetic records with ultra-high resolution sediments from N. Icelandic (MD99-2269) and E. Greenlandic (MD99-2322) continental margins, Icelandic lake sediments and archeomagnetic records from European and North American, which provide a good proxy for a geomagnetic input signal. These deep-sea RPI and PSV records from sites with moderate sedimentation rates (10-30 cm/kyr), comparable to those of commonly used deep-sea paleomagnetic records, show that we cannot accurately resolve features at less than a multi-millennial scale (∼2000 yrs). While spectral analyses indicate that a sedimentation rate of >50 cm/kyr is necessary to begin resolving millennial scale variability and that a sedimentation rate of at least ∼100 cm/kyr is necessary to resolve sub-millennial scale variability, suggesting that much of the geomagnetic record remains unobserved.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Atlantic Ocean; Expedition 303; Expeditions 303/306; IODP Site U1305; Integrated Ocean Drilling Program; Marine sediments; North Atlantic; Northwest Atlantic; Paleomagnetism; Sediments
Coordinates: N572800 N572900 W0483200 W0483200
Record ID: 2014093143
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