CarriageTowneNews.com, Kingston, NH

Online Extras: News to Note

July 16, 2013

Stutters in Earth's spin changed length of days slightly

Three times in the past decade, the Earth's spin has missed a beat as seemingly random blips cause days to temporarily stretch and shrink. They have emerged from the clearest-ever view of how long a day is.

Earth's rotations fluctuate as the oceans and the atmosphere push and tug on the spinning planet. But these small daily variations hide longer-term patterns.

Richard Holme of the University of Liverpool looked at 50 years of GPS and astronomical data to see how day length varied during that time. His analysis highlighted a well-known cycle of slow changes at the Earth's core, which lengthen days by a few milliseconds over roughly a decade, then shorten them again.

There's also a 5.9-year cycle, due to persistent friction between the Earth's fluid outer core and its surrounding mantle, a wobble that changes day length by fractions of milliseconds a year.

When Holme stripped away both of these regular cycles, though, sudden unexpected jumps in day length emerged from his calculations. Three times in recent years - in 2003, 2004 and 2007 - our planet's spin has stuttered. The jumps interrupted the longer-term changes by a fraction of a millisecond, and they lasted several months before going back to normal.

Satellite readings of the planet's magnetic field over the past 20 years show that the field also undergoes sudden jerks, and Holme found that they coincide with the jumps in the Earth's spin. He says the sudden changes probably occur when a patch of molten outer core temporarily sticks to the mantle, causing a steep change in angular velocity.



 

1
Text Only
Online Extras: News to Note

New England News
Obituaries
  • Marie Rose (Robidoux) Audy

    LAWRENCE — Marie Rose (Robidoux) Audy, passed away at her home surrounded by her family, after suffering a stroke in April. She was born in Lawrence and was the daughter of the late Rose A. (Betit) and Alfred Robidoux, originally of Quebec, Canada. She was predeceased by her husband of 28 years, Armand Joseph Audy, who passed away on June 28, 1976.

    Continued ...
    5 days
  • Charles Anthony "Chuck" Carnival, 79

    Jackson, MS — Charles Anthony “Chuck” Carnival, 79, formerly of Raymond, N.H., passed away Thursday, June 19, 2014, at Central Mississippi Medical Center in Jackson, Miss.

    Continued ...
    12 days 1 Photo
  • Francis M. Lurvey, 76

    Bar Harbor, ME — Francis M. Lurvey passed away Sunday, June 22, in Bar Harbor, Maine, after battling cancer. By his side were his sons, Edwin Lurvey and Steven Lurvey and his niece and husband, Debra and Richard Carey, as well as cousin, Marion McDonald. He was the son of Edwin R Lurvey (Bar Harbor) and Delia Amazeen (Dexter). He is survived by five children, a stepson, and their families. His sons, Edwin and wife April, Steven and wife, Pam, David and his daughter, Meghan, as well as his daughters, Lorraine and Ellen and her husband, Paul DiScipio with daughters, Katherine and Julia, and his stepson, Brian Faulkner and wife, Jody with children, Trevor, Rachel, and Keith. He is also survived by his sister, Sheryl, and many nieces and nephews including Frank Lurvey and Elaine Langer. Francis was predeceased by his twin brother, Frank, as well as his brothers, Edwin and Erwin. He was also predeceased by his longtime companion, Brian and Edwin’s mother, Maureen Faulkner and former wife, Roberta Lurvey Gilmore.

    Continued ...
    19 days 1 Photo
  • Norman R. Cote

    Atkinson, NH — Norman R. Cote, of Atkinson, was called to his heavenly home on June 16, 2014, following a period of declining health.

    Continued ...
    19 days
  • Frederick M. Hopper, 64

    Epping, NH — Frederick Michael Hopper, of Epping, N.H., passed away unexpectedly on Sunday, June 15, 2014. Predeceased by his wife, Alice Hopper, he is survived by his longtime girlfriend, Joann Peatfield; daughters, Shay Belair and Jayne Pond; sons-in-law, Adam Belair and James Pond; mother, Arlene Hopper; father and stepmother, Frederick S. and Barbara Hopper; siblings, Susan Hardy, Stephan Hopper, Scott Hopper, and Sherri Chagnon; grandsons, Benjamin Belair, Jonathan Belair and Jackson Pond; and numerous nieces and nephews.

    Continued ...
    26 days 1 Photo

Stocks