IRIS EPO

For educators, college/university faculty and professionals interested in the instruction of seismological concepts in primary and secondary classrooms.

This list has moved to the Monthly Educator Newsletter at http://eepurl.com/ijjmVL
Email address
irisepo@lists.ds.iris.edu
Type
Subscribers
1078
Moderated by
Tammy Bravo,
Related tags
None
December
November
October
September
August
July
June
May
April
March
February
January
December
November
October
September
August
July
June
May
April
March
February
January
December
November
October
September
August
July
June
May
April
March
February
January
December
November
October
September
August
July
June
May
April
March
February (1)
January
December
November
October
September
August
July
June
May
April
March (2)
February (1)
January (1)
December
November
October (1)
September
August
July
June (1)
May
April (1)
March (1)
February
January
December
November
October
September
August
July
June
May
April
March
February
January
December
November
October
September
August
July
June
May
April
March (1)
February
January
December
November
October
September
August
July
June (1)
May
April (2)
March (1)
February
January
December
November
October (1)
September
August
July
June
May
April
March (1)
February
January
December
November
October (2)
September
August
July
June
May
April
March (1)
February
January
December
November
October (1)
September
August
July
June (1)
May (2)
April (1)
March
February
January
December
November (1)
October
September (1)
August
July
June
May
April
March
February
January (2)
December
November
October (1)
September (1)
August
July
June
May (1)
April (1)
March (1)
February
January
December
November
October
September (3)
August
July
June
May
April
March
February
January (4)

Active Message Threads for May 2007

John or Jan Lahr
2007-05-03 16:25:27 - 2007-05-03 22:33:57
Hi Chris, Good questions. For the helicorder view AmaSeis only allows one filter to filter out high frequencies and one to filter out low frequencies. For example, if you want to enhance the high frequency signals from local events on your helicorder record, you might filter out frequencies below 1.5 Hz, which leaves frequencies between 1.5 Hz and 3 Hz. (Note that because we are only sampling at 6 Hz, the highest frequency that can be resolved is 3 Hz.) The bottom of the helicorder re… [more]
Replies
John or Jan Lahr
2007-05-03 06:30:09 - 2007-05-03 15:37:20
A while back I showed how to set up a helicorder filter in AmaSeis so that the surface waves from distant earthquakes would be enhanced. (See: http://jclahr.com/science/psn/as1/filtering/index.html) The other day I received an earthquake notification message* from the USGS about a 3.1 earthquake not too far from my station in Corvallis, Oregon. Although I couldn't see anything on my helicorder record, especially with the filter I was using to enhance low frequencies, by switching to a f… [more]
Replies
17:33:41 v.b4412d20