FN Archimer Export Format
PT J
TI Geomagnetic field behavior during the Iceland Basin and Laschamp geomagnetic excursions: A simple transitional field geometry?
BT 
AF LAJ, C
   KISSEL, C
   ROBERTS, AP
AS 1:1;2:1;3:2;
FF 1:;2:;3:;
C1 CEA, CNRS, UVSQ, Lab Sci Climat & Environm, F-91198 Gif Sur Yvette, France.
   Univ Southampton, Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England.
C2 CEA, FRANCE
   NOC, UK
IF 2.384
TC 87
UR https://archimer.ifremer.fr/doc/00239/34977/33475.pdf
LA English
DT Article
CR IMAGES 1-MD101
   IMAGES V LEG 1-MD114
   IMAGES V LEG 4-MD114
   MD 127 / PAGE
   PACIMA - MD 79
BO Marion Dufresne
DE ;virtual geomagnetic paths
AB [1] We present four new records of the Iceland Basin Excursion (IBE) and five new records of the Laschamp Excursion (LE) obtained from rapidly deposited marine sediments in the North Atlantic Ocean, the Nordic Seas, the Gulf of Mexico, the South China Sea, and the southern Indian Ocean. Marked minima in relative paleointensity correspond with the paleomagnetic directional changes associated with all of the excursion records. The virtual geomagnetic pole (VGP) paths of the four IBE records are all similar. The VGPs move southward over Europe and Africa, reaching the southern hemisphere (three reach Antarctica), and then move to more eastern longitudes before returning northward over Australia and east Asia, describing a large counterclockwise loop. The same VGP pattern is observed in other published records. The VGP paths observed for the LE are similar to those of the IBE; however, they loop clockwise instead of counterclockwise. Despite the different sense of looping, the marked similarity among the paths for the two excursions suggests that a similar, relatively simple geometry dominated the transitional field during both the IBE and the LE. Similar dynamo mechanisms must therefore have been active in the Earth's core for both excursions. The duration of the excursions is estimated at < 2,000 years, which supports the suggestion that a difference exists between the mechanisms for excursions and reversals. However, the coincidence of the longitudinal bands for VGPs associated with excursions compared to some reversal paths could also indicate an inherent link between the mechanisms for reversals and excursions.
PY 2006
PD MAR
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU Amer Geophysical Union
VL 7
IS 3 / Q03004
UT 000236268500002
BP 1
EP 17
DI 10.1029/2005GC001122
ID 34977
ER

EF