Geomagnetic reversal dating

14-Sep-2016 16:49 by 5 Comments

Geomagnetic reversal dating

Therefore, the results can be biased by artifacts that are not always fully understood so that many observations remain controversial.

What are the major unsolved or unresolved questions and where are additional data or modeling efforts needed?

These magnetic data are of value to paleomagnetists in reconstructing past geomagnetic fields and, more specifically, in constraining the structure and geometry of the transitional field more accurately.

Studies of geomagnetic polarity reversals have generated huge debates in the paleomagnetic and wider solid Earth geophysics communities over the last 25 years.

AGU asked the authors of the article to highlight the important results that have emerged from their research and some of the important questions that remain. What recent advances in particular are leading to a new understanding or synthesis?

Reversals are one of the most enigmatic characteristic of the earth’s magnetic field and as so they generate many questions.

Therefore, determining the structure and processes associated with geomagnetic reversals is essential for a full understanding of the geodynamo processes.

Typical timescales that characterize polarity reversals constrain the fluid dynamical timescales and hence our knowledge of the earth’s core.However reversals occur over a few thousand years at most and it is a real challenge to acquire detailed information over this short transitional period between the two polarities.In fact, there is no perfect magnetic recorder, most sediments are characterized by low temporal resolution and volcanism is sporadic in nature with lava flows irregularly distributed in time.We learned also that field geometry during the transition is much more complex with several poles wandering at the surface of the earth and can thus be described as a multipolar field.However it is very difficult to obtain a good description of the field geometry (quadrupolar, octopolar etc…) and to describe its time-evolution.How often do reversals occur and how long do they last? Does the field weaken or collapse and then recovers with the opposite polarity?