Record Details

Micrometeorite flux on Earth during the last ~50,000 years

DRS at CSIR-National Institute of Oceanography

View Archive Info
 
 
Field Value
 
Title Micrometeorite flux on Earth during the last ~50,000 years
 
Creator ShyamPrasad, M.
Rudraswami, N.G.
Panda, D.K.
 
Subject extraterrestrial material
cosmic spherules
ocean floor
sediment analysis
 
Description Flux of micrometeorites is estimated by using cosmic spherule counts from a seafloor area of 2.50 ms2 from the Indian Ocean. The spherules are recovered from sediment samples in close-spaced locations from the Indian Ocean after sieving 293kg of sediment. The terrestrial age of the spherules has a range of 0–~50,000 years. The spherules have a size range of 57–750µm (average size 265±92µm). The diameter of the spherules increases from scoriaceous-barred-cryptocrystalline-glassy types. The time-averaged flux of the spherules is 160t/yr, a sizeable mass (>60%) resides in the >300µm fraction; the slope of distribution is similar to that of Deep-Sea Spherules but significantly different from other collections which have lower average diameters. It is observed here, a significant population of cosmic dust resides in the larger sizes which can be recovered by sampling large areas in time and space. The spherule textures are similar to that of unbiased collections from the polar regions, indicating that the textural types of cosmic dust that have been raining on the Earth during the last 50 kyr have been constant regardless of size. Major element chemistry of a majority of the spherules show elemental ratios that are close to a CM or CI chondritic parent body; a single spherule (0.2% of the population) suggests an achondritic parent body. Unbiased collections spanning large areas temporally and spatially enlarge the inventory of the Earth-crossing meteoroid complex and provide valuable inputs for models on cosmic dust accretion.
 
Date 2014-01-07T12:18:53Z
2014-01-07T12:18:53Z
2013
 
Type Journal Article
 
Identifier Journal of Geophysical Research (E: Planets), vol.118(11); 2013; 2381-2399
no
http://drs.nio.org/drs/handle/2264/4419
 
Language en
 
Relation J_Geophys_Res_E_118_2381.jpg
 
Rights An edited version of this paper was published by AGU. Copyright [2012] AGU. To view the published open abstract, go to http://dx.doi.org/10.1002/2013JE004460
 
Publisher American Geophysical Union