“Earthquakes generate elastic waves when one block of material slides against another; the break between the two blocks being called a fault.”
Explosions generate elastic waves by an impulsive change in volume in the material. Small explosive charges are used in controlled-source seismic experiments in which the waves penetrate only a few kilometres into the earth.
[Seismology and plate tectonics, 1990, http://books.google.com/books?id=tZRxPzwoChIC&pg=PA12] (p. 12)
Seismology and Plate Tectonics (1990)
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David Gubbins 6
British university teacher 1947Related quotes
[Seismology and plate tectonics, Cambridge, UK; New York, Cambridge University Press, 1990, http://books.google.com/books?id=tZRxPzwoChIC&pg=PA4] (pp. 4–5)
Seismology and Plate Tectonics (1990)

“Great," I said. "Another conference call. I havegot to start blocking your number.”
Source: Last Sacrifice

Un Art de Vivre (The Art of Living) (1939), The Art of Growing Old
“blocked. blocked. blocked. youre all blocked. none of you are free of sin”
[ Link to tweet https://twitter.com/dril/status/473706394009759744]
Tweets by year, 2014

Mount Madonna Messenger
'Rhymes's Reason':a guide to English Verse Yale University Press, 1981

“Not merely a chip of the old 'block', but the old block itself.”
Nathaniel Wraxall, "Historical Memoirs of My Own Time", part 2.
Edmund Burke's reaction to Pitt's maiden speech in Parliament. The 'old block' was William Pitt the Elder.
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“He was not merely a chip of the old Block, but the old Block itself.”
On Pitt's First Speech (26 February 1781), from Wraxall's Memoirs, First Series, vol. i. p. 342
1780s