Signals associated with tidal cycles could potentially provide advanced warning of certain types of volcanic eruptions.
A new study shows that just before a surprise eruption of New Zealand’s Ruapehu volcano in 2007, seismic tremors near its crater became tightly correlated with twice-monthly changes in the strength of tidal forces.Hmmmm....
“Looking at data for this volcano spanning about 12 years, we found that this correlation between the amplitude of seismic tremor and tidal cycles developed only in the three months before this eruption,” says Társilo Girona, a NASA postdoctoral fellow at the Jet Propulsion Laboratory who led the research during a postdoctoral appointment at Brown University.
“What that suggests is that the tides could provide a probe for telling us whether or not a volcano has entered a critical state,” Girona explains.
Shifting tides
Earth’s tides rise and fall daily due to the gravitational tug of the moon as the Earth rotates. During full and new moons, the lunar gravitational pull lines up with that of the sun, which makes the daily tidal bulges a little larger. During the first- and third-quarter moons, the daily tidal bulge is a little smaller.
This twice-monthly change in tidal amplitude is sometimes referred to as the fortnightly tide.
While we normally think of tides in terms of rising and falling waters, these gravitational stresses also affect the planet’s solid crust. The question of whether gravitational stresses may influence volcanic activity is longstanding in the Earth sciences....MORE
Accuweather tells us there's something cookin' on Wednesday:
Super blue moon to coincide with lunar eclipse for 1st time in 150 years
A blue moon, a supermoon and a lunar eclipse will all fall on the same night at the end of January in an event that hasn’t happened in over 150 years.
These three lunar events separately are not uncommon, but it is rare for all three to occur at the same time. The last time that there was a blue moon, a supermoon and a total lunar eclipse at the same time for North America was on March 31, 1866....
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For the scientifically inclined, Space.com has more.
Me, I think I'm going to track down that volcano insurance fellow.