Kurt's Weblog

Nature - 22 Dec 2005

We were beaten to this one... The one this I would like to emphasize is that we need to send many more robots to Mars!!!

  Nature 438, 1123-1128 (22 December 2005) | doi:10.1038/nature04383
  Impact origin of sediments at the Opportunity landing site on Mars


  L. Paul Knauth, Donald M. Burt and Kenneth H. Wohletz


  Mars Exploration Rover Opportunity discovered sediments with layered
  structures thought to be unique to aqueous deposition and with
  minerals attributed to evaporation of an acidic salty
  sea. Remarkable iron-rich spherules were ascribed to later
  groundwater alteration, and the inferred abundance of water
  reinforced optimism that Mars was once habitable. The layered
  structures, however, are not unique to water deposition, and the
  scenario encounters difficulties in accounting for highly soluble
  salts admixed with less soluble salts, the lack of clay minerals
  from acid-rock reactions, high sphericity and near-uniform sizes of
  the spherules and the absence of a basin boundary. Here we present a
  simple alternative explanation involving deposition from a
  ground-hugging turbulent flow of rock fragments, salts, sulphides,
  brines and ice produced by meteorite impact. Subsequent weathering
  by intergranular water films can account for all of the features
  observed without invoking shallow seas, lakes or near-surface
  aquifers. Layered sequences observed elsewhere on heavily cratered
  Mars and attributed to wind, water or volcanism may well have formed
  similarly. If so, the search for past life on Mars should be
  reassessed accordingly.

The same issue of Nature has an article backing the story of water on mars:

Phyllosilicates on Mars and implications for early martian climate


  F. Poulet, J.-P. Bibring, J. F. Mustard, A. Gendrin,
  N. Mangold, Y. Langevin, R. E. Arvidson, B. Gondet and C. Gomez 


  The recent identification of large deposits of sulphates by remote
  sensing and in situ observations has been considered evidence of the
  past presence of liquid water on Mars. Here we report the
  unambiguous detection of diverse phyllosilicates, a family of
  aqueous alteration products, on the basis of observations by the
  OMEGA imaging spectrometer on board the Mars Express
  spacecraft. These minerals are mainly associated with Noachian
  outcrops, which is consistent with an early active hydrological
  system, sustaining the long-term contact of igneous minerals with
  liquid water. We infer that the two main families of hydrated
  alteration products detected-phyllosilicates and sulphates-result
  from different formation processes. These occurred during two
  distinct climatic episodes: an early Noachian Mars, resulting in the
  formation of hydrated silicates, followed by a more acidic
  environment, in which sulphates formed. 

There is also an article entitled "Planetary science: Clays in the history of Mars," but the link is broken.

OGC Dec News

  ... OGC profiles don't quite scratch everyone's itch. GeoRSS; W3C's
  Basic Geo (WGS84 lat/long) Vocabulary; efforts to "geotag" IP
  addresses (the .geo proposal and the Go2 coordinates proposal);
  efforts to geotag images; and proposals to put spatial capabilities
  in the next revision of the Internet Protocol, IPv6; -- not to
  mention Google's KML -- together testify to the variety of
  perspectives that different people can have on something that seems
  like it ought to be very simple. In our business, we are never
  allowed to forget that different communities have different
  requirements.

I know I am not really doing a web log right now, but this needs documentating! I need to get the s tensor + sigma for doing a bootams on each stratigraphic unit. Up until now, I did the rotation of the eigenvectors on my own in python. Rotating vectors around a vertical pole of rotation is pretty easy.

I did PCA on the AF demagnetizations of the NRM. Then I did a gofish to get the mean declination to remove. I got 24.4° With a little help from Lisa, I created a new k15 entry for the sample. First the original sample:

ttn136b-01pw-s2-005  ajharris    3/14/02  1:15:55 PM  
9.790000E+1  9.835000E+1  9.815000E+1  9.750000E+1  9.810000E+1  
9.715000E+1  9.555000E+1  9.785000E+1  9.715000E+1  9.550000E+1  
9.660000E+1  9.615000E+1  9.475000E+1  9.655000E+1  9.600000E+1  

Now, I need to replace the stuff after the sample name with correct rotation. Going through the database changes how the numbers are formated, but they are really the same.

ttn136b-01pw-s2-005 24.4 0 0 0
97.9 98.35 98.15 97.5 98.1 
97.15 95.55 97.85 97.15 95.5 
96.6 96.15 94.75 96.55 96.0 

Now I need to convert the new k15 file to rotated eigenvectors to check the value.

# k15_s -g < new.k15 | s_eigs
0.32516053  101.64   76.43 0.33633894  341.95    6.82 0.33850062  250.54   11.68

And to check the rotation, I dumped the ams_geo table's V3 dec inc:

# cat new.k15.check 
101.6 76.4 ttn136b-01pw-s2-005

Finally, here are my new s matrix values that I can pass (along with its cousins) to bootams.

# k15_s -g < new.k15
0.33654407 0.33759156 0.32586446 0.00077286 -.00290113 0.00037149 0.00045243

I put all this in writeK15withRot.py for now. This program will hopefully see the light of day after I graduate.

I though Nulls in SQL might be a bit confusing. Turns out that a really simple case is no big deal, but all the details can make things very confusing. SQLite has a Null Handling page which show how things can get confusing. My simple case worked out pretty well. I have samples where only the bulk susceptibility has been measured. These samples do not have tau[123] and all the other AMS parameters. I do not want those samples messing up otherwise nice code.

  sqlite ttn136b.db 'SELECT samplename,bulksusc,tau1 FROM ams \
     WHERE corenum=5 AND tau1 NOT NULL'

Geopodcasting and Geotagged Sounds

  A discussion about Geopodcasting on the Geowanking mailing list
  pointed to geotagged sounds on Freesound. Sounds are mapped on
  Google Map. From the discussion: "Imagine if there were
  geopodcasts. That is, bits of audio ABOUT a place annotated with the
  location OF the place. Then, when you asked Google for trip
  directions, it would also give you an RSS feed of URLs pointing to
  geopodcasts along the route of your trip. Then you could suck them
  down to your laptop. Using a GPS receiver and the appropriate
  software, it would play the audio file, timing it so that the file
  stopped playing when you got to the place described."

Been wanting this in cars for about 10 years now. Drive by a location and if the topic matches your list of interests, then it plays. Perfect for Sunday drives or moving across the country.

  Lockheed Martin reveals Cormorant details


  Lockheed Martin has revealed new details of Cormorant, a unique
  unmanned combat air vehicle (UCAV) designed to be launched and
  recovered from a submerged submarine. Key technologies for Cormorant
  -- also known as the Multi-Purpose UAV (MPUAV) -- are being
  demonstrated under a 16-month Phase 1 contract issued to Lockheed
  Martin and its team-mates (including General Dynamics Electric Boat)
  in May 2005. 

The above is from Jane's digest. If this thing is easy to lauch from a sub, would it be easy to launch and retrieve from a research ship? And would it be a good platform for a magnetometer?

I am getting down to the wire on my PhD. Unfortunately, this means that I have a negative amount time available to anything else until this thing gets submitted. Plus, I need to come up with another server. My blog may be back in about Feb.

Thanks to barcode and all the others that have said that they liked/enjoyed/used my blog. It has been fun. I expect that if/when I bring my blog back, it will be with my own blogging software that is written in python. Nanoblogger has treated me well, but it is time to put some research energy into the methods and styles of weblogs/worklogs (klogs?).

This blog and all of my other content on schwehr.org is going away in the next two weeks.

Debi has said that she is willing to host the archives of this blog, but it will be a month or two before I can sort out the articles that are no acceptable for display on a UCSD site.

This blog and schwehr.org will be offline in less than two weeks and there will be no more updates.

TTFN -kurt

Grumble grumble solaris grumble.

The old solaris Blade 100 machines that I setup a couple years ago got hacked. I am thinking that they got in through the xserver with a xhost command. I have not been doing the maintanence on the machine in a couple years, so I don't know the machines exact configuration. It will be interesting to see the forensic report.

Depressing.