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
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 December 2006

ChrisAtUpw@aol.com
2006-12-31 19:52:07
In a message dated 31/12/2006, jerdell@cox.net writes: Greetings, I am trying to understand the band pass filters and have a few questions. 1. John Lahr stated that; “Since the AS-1 samples the amplitude of the seismic signal about 6 times per second, clearly high frequencies will not be well represented. The highest frequency that it's theoretically possible to record faithfully is one half of the sample rate.” You interpret this as six/2 = max frequency = 3Hz You tend not t… [more]
No replies
jerdell@cox.net
2006-12-31 05:22:16 - 2006-12-31 18:57:23
Greetings, I am trying to understand the band pass filters and have a few questions. 1. John Lahr stated that; "Since the AS-1 samples the amplitude of the seismic signal about 6 times per second, clearly high frequencies will not be well represented. The highest frequency that it's theoretically possible to record faithfully is one half of the sample rate." So if a sample is taken every .17 seconds (6 times per second) and you divide that in half you get .33seconds. Therefore seismic… [more]
Replies
jerdell@cox.net
2006-12-31 00:40:10
Greetings and Happy New Year, I just wanted to share with everyone a problem I had with my AS-1 and the solution. I left for China on Aug 10th and as soon as I got to Chengdu and checked the school seismograph; http://www.pcds.org/share/earthquake/ it had stopped working. The seismograph was not recording anything; it was if the seismometer was no longer connected to the CPU. The next day I checked back and it was recording but the trace was wandering across the screen like a chicken in a… [more]
No replies
Alan Jones
2006-12-15 01:45:34
Neat story on sounds of the entire earth speeded up so you can hear them. Check out: http://www.npr.org/templates/story/story.php?storyId=6615446 Alan
No replies
John or Jan Lahr
2006-12-02 22:59:42
Below is an excerpt from December newsletter of the Windows to the Universe program. http://www.windows.ucar.edu/ Second Anniversary of South-East Asian Tsunami by <http://www.windows.ucar.edu/tour/link=/bio/Roberta.html>Roberta December 26th brings the second anniversary of the <http://www.windows.ucar.edu/tour/link=/headline_universe/earth_science/stories_2004/tsunami_news.html>massive tsunami in 2004 which brought destruction and death to many countries bordering the Indian Ocean i… [more]
No replies
18:15:51 v.22510d55