Is each day is really shorter?

Dear Control Engineering: I heard something about the recent earthquake in Chile affecting the earth’s rotation. What’s that about?


Dear Control Engineering: I heard something about the recent earthquake in Chile affecting the earth’s rotation. What’s that about?As strange as it sounds, NASA believes that the movement of the tectonic plates of the earth that caused the earthquake in Chile on February 27 has shifted the position of the earth’s axis and its rotation has speeded up. The Jet Propulsion Laboratory has reported that its calculations suggest that the earth’s figure axis, which is the axis on which our planet’s mass balances, shifted by about 3 inches during the earthquake. With that shift, the earth’s diameter has actually gotten smaller. This change has caused the earth’s rotation to speed up causing a day to be slightly shorter. The emphasis is on slightly, since the difference is a whopping 1.26 microseconds.

The JPL came to a similar conclusion after the big earthquake in Sumatra in 2004. Most of the news surrounding that quake was about the resulting Tsunami, but it was caused by a massive shift on the sea floor. The change in a day’s length was much more dramatic following that event at 2.68 microseconds. Such changes can’t really be measured, but they can be calculated.

So, feel free to leave work early.

Posted by Ask Control Engineering on March 6, 2010

No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Controller programming; Safety networks; Enclosure design; Power quality; Safety integrity levels; Increasing process efficiency
Additive manufacturing benefits; HMI and sensor tips; System integrator advice; Innovations from the industry
Robotic safety, collaboration, standards; DCS migration tips; IT/OT convergence; 2017 Control Engineering Salary and Career Survey
Featured articles highlight technologies that enable the Industrial Internet of Things, IIoT-related products and strategies to get data more easily to the user.
This article collection contains several articles on how automation and controls are helping human-machine interface (HMI) hardware and software advance.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Mobility as the means to offshore innovation; Preventing another Deepwater Horizon; ROVs as subsea robots; SCADA and the radio spectrum
Future of oil and gas projects; Reservoir models; The importance of SCADA to oil and gas
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me