Cosmic Dust Raining on the Earth

Morris is fond of citing figures that indicate that about five million metric tonnes of cosmic dust falls on the earth each year. He calculates that over five billion years, we should have accumulated a layer of dust 55 m (182 feet) thick! But if you do the calculation correctly (which Morris does not), it amounts to only a shoebox full of dust over an entire square kilometer. This is so minuscule it can barely be detected even in the best sedimentary records from deep-sea cores, which are undisturbed and have extremely low sedimentation rates (the only place so little dust could be detected). In shallow marine or terrestrial sediments, which are highly mixed and weathered, this tiny amount of dust would be homogenized quickly.

Notes:

How much and to what effect?

Folksonomies: geology layers cosmic dust

Taxonomies:
/food and drink/food/grains and pasta (0.417267)
/business and industrial/energy/oil (0.377518)
/science/geology/seismology/earthquakes (0.219360)

Keywords:
Cosmic Dust Raining (0.995994 (negative:-0.733438)), entire square kilometer (0.662354 (negative:-0.318263)), extremely low sedimentation (0.644037 (negative:-0.555517)), best sedimentary records (0.628564 (negative:-0.564200)), metric tonnes (0.459417 (negative:-0.551115)), deep-sea cores (0.425104 (negative:-0.564200)), terrestrial sediments (0.420805 (negative:-0.326329)), shallow marine (0.399866 (negative:-0.326329)), Morris (0.250080 (negative:-0.456004)), earth (0.221819 (negative:-0.642276))

Entities:
Morris:Person (0.923030 (negative:-0.456004)), five billion years:Quantity (0.923030 (neutral:0.000000)), 182 feet:Quantity (0.923030 (neutral:0.000000)), 55 m:Quantity (0.923030 (neutral:0.000000))

Concepts:
SI prefix (0.927644): website | dbpedia
Geology (0.833750): dbpedia | freebase | opencyc
Uranium (0.826616): dbpedia | freebase | opencyc
Earth (0.815380): dbpedia | freebase

 Evolution
Books, Brochures, and Chapters>Book:  Prothero , Donald R. and Buell , Carl Dennis (2007), Evolution, Columbia Univ Pr, Retrieved on 2012-04-13
  • Source Material [books.google.com]
  • Folksonomies: science