Editing Magnetohydrodynamics (section)

====Earthquakes====
Some monitoring stations have reported that [[earthquakes]] are sometimes preceded by a spike in [[ultra low frequency]] (ULF) activity.  A remarkable example of this occurred before the [[1989 Loma Prieta earthquake]] in [[California]],<ref>{{cite journal |first1=Antony C. |last1=Fraser-Smith |first2=A. |last2=Bernardi |first3=P. R. |last3=McGill |first4=M. E. |last4=Ladd |first5=R. A. |last5=Helliwell |first6=O. G. |last6=Villard Jr. |date=August 1990 |title=Low-Frequency Magnetic Field Measurements Near the Epicenter of the M<sub>s</sub> 7.1 Loma Prieta Earthquake |journal=[[Geophysical Research Letters]] |volume=17 |issue=9 |pages=1465–1468 |issn=0094-8276 |oclc=1795290 |access-date=December 18, 2010 |url=http://ee.stanford.edu/~acfs/LomaPrietaPaper.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://ee.stanford.edu/~acfs/LomaPrietaPaper.pdf |archive-date=2022-10-09 |url-status=live |doi=10.1029/GL017i009p01465 |bibcode=1990GeoRL..17.1465F}}</ref> although a subsequent study indicates that this was little more than a sensor malfunction.<ref>{{Cite journal | last1 = Thomas | first1 = J. N. | last2 = Love | first2 = J. J. | last3 = Johnston | first3 = M. J. S. | title = On the reported magnetic precursor of the 1989 Loma Prieta earthquake | doi = 10.1016/j.pepi.2008.11.014 | journal = Physics of the Earth and Planetary Interiors | volume = 173 | issue = 3–4 | pages = 207–215 |date=April 2009 | bibcode=2009PEPI..173..207T}}</ref> On December 9, 2010, geoscientists announced that the [[Demeter (satellite)|DEMETER]] satellite observed a dramatic increase in ULF radio waves over [[Haiti]] in the month before the magnitude 7.0&nbsp;M<sub>w</sub> [[2010 Haiti earthquake|2010 earthquake]].<ref>{{cite web|url=http://www.technologyreview.com/blog/arxiv/26114/|title=Spacecraft Saw ULF Radio Emissions over Haiti before January Quake|author=KentuckyFC <!-- blogger's legitimate nom de plume -->|date=December 9, 2010|website=Physics arXiv Blog|publisher=[[TechnologyReview.com]]|location=[[Cambridge, Massachusetts]]|access-date=December 18, 2010}}  {{Cite journal|last1=Athanasiou|first1=M|last2=Anagnostopoulos|first2=G|last3=Iliopoulos|first3=A|last4=Pavlos|first4=G|last5=David|first5=K|year=2010|title=Enhanced ULF radiation observed by DEMETER two months around the strong 2010 Haiti earthquake|journal=Natural Hazards and Earth System Sciences|volume=11|issue=4|pages=1091|arxiv=1012.1533|doi=10.5194/nhess-11-1091-2011|bibcode=2011NHESS..11.1091A|s2cid=53456663|doi-access=free}}</ref> Researchers are attempting to learn more about this correlation to find out whether this method can be used as part of an early warning system for earthquakes.