Comments for The Volcanism Blog

Comment on Chaitén update, 20 August 2008 by Brian

Brian — Wed, 20 Aug 2008 23:22:33 +0000

I am not an expert, but figure 4 looks a lot like the pattern Mt. St. Helens had during the dome building eruption a couple of years ago. Scientists talked about the “drumbeat” rythym of the earthquakes, with the occasional rockfall thrown in. I could be dead wrong of course.

http://news.nationalgeographic.com/news/2006/11/061122-volcanoes.html

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Eruption04/Monitoring/February2008/SEP_SHZ_CC.2005032000.gif

Comment on Local voices from Chaitén: allchile.net by Rolly Robbins

Rolly Robbins — Wed, 20 Aug 2008 23:12:10 +0000

Thank’s for all the info you post about the chaiten volcano. I live in the U.S.A and vacation in Chile. south of Chaiten. Thhanks again.

Best Regards
Rolly Robbins

Comment on Local voices from Chaitén: allchile.net by volcanism

volcanism — Wed, 20 Aug 2008 11:04:32 +0000

Thank you! I’m very glad you have found the blog useful. I’ll do my best to ensure that Chaitén coverage here will continue for as long as it’s needed.

Comment on Local voices from Chaitén: allchile.net by Helen

Helen — Tue, 19 Aug 2008 16:40:27 +0000

You acquired a bunch of avid readers from All Chile, I really missed you while you were away! Huge Thanks for all the the great information and translations and comments.

I’m Chilean by Birth but live in Puerto Rico so I watch Montserrat also (through teary SO2 agravated eyes)

Comment on Sulphur dioxide far and wide by Brian D

Brian D — Mon, 18 Aug 2008 23:13:26 +0000

Check out how this cloud has dispersed since the eruption here.

http://satepsanone.nesdis.noaa.gov/pub/OMI/OMISO2/index.html

Comment on Chaitén: SERNAGEOMIN report, 13 August 2008 by volcanism

volcanism — Mon, 18 Aug 2008 18:56:29 +0000

Thanks for the Seisan information - that makes it much clearer (even if ‘elliptical error ellipses’ is somewhat tautological). And I take your point about the pitfalls of translation - that’s why it’s so helpful to get another perspective, such as you have provided. Thanks for your input, and for taking the time and trouble to look into the point further.

Comment on Chaitén: SERNAGEOMIN report, 13 August 2008 by george wohanka

george wohanka — Mon, 18 Aug 2008 16:29:04 +0000

Did a search on Seisan Program mentioned in release 48. It refers directly to elliptical error ellipses. So that resolves it for me. To those who found this exchange boring or worse, I am sorry.

Routine Processing of Seismic Data

The main work of a seismic observatory is to process and organize incoming data from different sources quickly. SeisAn has a simple, time-ordered database and a set of programs for processing the data. SeisAn can navigate in the database to find a given event or do housekeeping (splitting, merging, and deleting events). Once an event has been selected, a large number of options are available, like phase picking, earthquake location, fault plane solution, inserting macroseismic information, etc. Results of the interactive processing are stored back in the database. The signal processing tool can be used to pick phases and amplitudes, correct for instrument response, produce Wood-Anderson seismograms for determining ML, simulate WWSSN SP and LP records, determine azimuth of arrival for three-component stations or arrays (FK analysis), rotate seismograms, display theoretical arrival times for IASP91 phases to help identify global phases, and do spectral analysis. Earthquake location is done by Hypocenter (Lienert and Havskov, 1995). The program can use nearly all common crustal and global phases (8-character ISC codes), locate teleseismic events using the IASP91 model, and use observed azimuth and apparent velocity. The program can therefore be used with all types of input data, whether from single stations or seismic arrays. Hypocenters (and sections) can be plotted with elliptical error ellipses, and interactive selection of epicenters can be done from epicenter maps. There is also an interface to GMT for epicenter plotting. For general work, programs are available for database creation, input and output of large data sets, and conversion and manipulation of waveform data. SeisAn is particularly well suited for merging phase and waveform data from different sources.

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Taken from the above:

Hypocenters (and sections) can be plotted with elliptical error ellipses, and interactive selection of epicenters can be done from epicenter maps.

Comment on Chaitén: SERNAGEOMIN report, 13 August 2008 by george wohanka

george wohanka — Mon, 18 Aug 2008 13:07:01 +0000

Again I agree with all you have just posted. Also thought the term could refer to location error, but was unable to convince myself. Sure ruptura is rupture and onda is wave. But if and it is a big if , an ideomatic expression if involved a jump must be made into the unknown.

Some terms relating to siesmology propably did not exist in Spanish and were converted into Spanish from English.

The term fault come to mind. It is possible that the term faults could in some cases end up being converted into “erors” in Spanish and then back into errors if translated into English.

Yes, this is much more convoluted than just accepting that location errors were being referred to. Just that I had trouble understanding what location had been in error and was now moved to another location.

Appreciate your pointing out the use in reference to hypocentres.

Comment on Chaitén: SERNAGEOMIN report, 13 August 2008 by volcanism

volcanism — Mon, 18 Aug 2008 07:42:02 +0000

Thanks for this feedback on the translation - I am always keen to have suggestions as to how the translations I make here can be improved. The phrase ’surface error’ is a literal translation and isn’t very satisfactory, but I took it to be a reference to potential margins of error in locating the earthquakes - in the text it talks about ‘error’ in this way with reference to the hypocentres. Rupture would be ‘ruptura’ and wave (in the sense of seismic wave) is ‘onda’.

Comment on Chaitén: SERNAGEOMIN report, 13 August 2008 by george wohanka

george wohanka — Mon, 18 Aug 2008 02:00:36 +0000

After this I will just wait for a response but now think the ideomatic translation may be surface waves.

From Wikipedia ” Seismic wave

Earthquakes, and other sources, produce different types of seismic waves which travel through rock, and provide an effective way to image both sources and structures deep within the Earth. There are three basic types of seismic waves in solids: P-waves, S-waves (both body waves) and surface waves. The two basic kinds of surface waves (Rayleigh and Love), can be fundamentally explained in terms of interacting P- and/or S-waves.