Experimental determination of remanent magnetism of dusty ice deposits

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F20%3A00525411" target="_blank" >RIV/67985831:_____/20:00525411 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/20:10415795

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0012821X20303526#" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0012821X20303526#</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.epsl.2020.116408" target="_blank" >10.1016/j.epsl.2020.116408</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Experimental determination of remanent magnetism of dusty ice deposits

Popis výsledku v původním jazyce

Accumulations of ice and dust mixtures may acquire magnetization during deposition in a manner analogous to sedimentary rocks. Here, we consider the process of particles descending through an atmosphere and depositing in a preferential orientation that serves to record the ambient magnetic field during emplacement. We use a simple model for the settling and reorientation of ice particles with magnetic inclusions that includes magnetic torque, aerodynamic forces and gravity, to investigate the parameter space governing the process. For fields in the range of 10’s – 100’s μT we find that ice particles of sizes up to ∼100 μm which contain smaller magnetic grains as nuclei will produce a deposit indeed magnetized in the direction aligned with the applied field, but with a moment that is independent of the field strength. For particles in the 100’sμmrange, the magnetic moment increases with the field strength. To demonstrate the effect experimentally, we performed a suite of laboratory deposition simulations followed by measurements of the magnetic moment of the samples. We show that in the idealized laboratory conditions dusty ice magnetizes in the direction of the applied field, with the alignment increasing with its intensity. For the chosen conditions, the magnetization increases rapidly with field intensity in the range 10 – 200 μT, and approaches a maximal value above that. For a mixture with dust/ice ratio of 5 × 10−3 we obtained maximal magnetization values in the range 1.6 × 10 − 5 – 3 × 10−3 Am2/kg, depending on the distribution of particle sizes. We show that magnetic particle concentration in the ice determines the level of magnetic remanence, and conclude that the remanent magnetization of natural ice deposit in various settings may be measurable (if unobscured by post-depositional, wind, or other effects) and thus could provide a new paleomagnetic record on Earth and other planetary objects.

Název v anglickém jazyce

Experimental determination of remanent magnetism of dusty ice deposits

Popis výsledku anglicky

Accumulations of ice and dust mixtures may acquire magnetization during deposition in a manner analogous to sedimentary rocks. Here, we consider the process of particles descending through an atmosphere and depositing in a preferential orientation that serves to record the ambient magnetic field during emplacement. We use a simple model for the settling and reorientation of ice particles with magnetic inclusions that includes magnetic torque, aerodynamic forces and gravity, to investigate the parameter space governing the process. For fields in the range of 10’s – 100’s μT we find that ice particles of sizes up to ∼100 μm which contain smaller magnetic grains as nuclei will produce a deposit indeed magnetized in the direction aligned with the applied field, but with a moment that is independent of the field strength. For particles in the 100’sμmrange, the magnetic moment increases with the field strength. To demonstrate the effect experimentally, we performed a suite of laboratory deposition simulations followed by measurements of the magnetic moment of the samples. We show that in the idealized laboratory conditions dusty ice magnetizes in the direction of the applied field, with the alignment increasing with its intensity. For the chosen conditions, the magnetization increases rapidly with field intensity in the range 10 – 200 μT, and approaches a maximal value above that. For a mixture with dust/ice ratio of 5 × 10−3 we obtained maximal magnetization values in the range 1.6 × 10 − 5 – 3 × 10−3 Am2/kg, depending on the distribution of particle sizes. We show that magnetic particle concentration in the ice determines the level of magnetic remanence, and conclude that the remanent magnetization of natural ice deposit in various settings may be measurable (if unobscured by post-depositional, wind, or other effects) and thus could provide a new paleomagnetic record on Earth and other planetary objects.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Earth and Planetary Science Letters

ISSN

0012-821X

e-ISSN

—

Svazek periodika

545

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

11

Strana od-do

116408

Kód UT WoS článku

000549183200009

EID výsledku v databázi Scopus

2-s2.0-85086758388