An audio file of seismic events on 19th July 2008 using data recorded at the THS Seismometer (Dorchester, Dorset). Replay is speeded up by a factor of 2000 to make the seismic waves audible. P, S and Surface Waves are clearly audible from the main event against the microseismic background. The audio file covers a 24hr period. Two additional weaker events are also audible, occurring after the main event. There is an accompanying PDF file for 19th July 2008 showing AmaSeis analysis of the main event and Spectrogram analysis for the full 24hr period.

On checking through data on the KEYW seismometer which miraculously kept going all through the Christmas break  I spotted a nice record from a small event (Mw=5.3) in Northern Italy on 23rd Dec.   Very nice example of a regional event with a short duration and clearly identifiable P S and Surface waves.   Because this event is so close it contains lots of high frequency energy and shows up best with a high-pass filter (set to 2sec to remove all the 6sec microseismic noise) instead of the usual 10sec low pass filters used for teleseismic events

The 25 November 2008 issue of Eos (which has only just reached me) leads with an article called "Informatics and the 2007-2008 Electronic Geophysical Year" (Baker et al), which concludes with a plea for authors to submit papers that highlight informatics.  See also the eGY website.

(I am collecting a list of relevant journals for earth science informatics at http://delicious.com/jonblower/journals.)

The City of Manokwari,West Papua, was struck by a M 7.6 earthquake at 19:43:54 UT on the 3rd of January. The earthquake was caused by the thrust faulting as the Pacific plate subducted beneath the Australia plate along the NW coast of New Guinea. Several (5) aftershocks of between M4.8 and M5.6 followed. A M7.3 earthquake occured at 22:33:42 UT and is thought to have been triggered by the ealier event producing a "doublet". The helicorder trace on PAUL shows the two events, the red dots represent the occurence of each event.

The trace for each earthquake is shown below;

0901031943PAUL.sac

0901032233PAUL.sac

The BBC world news channel reports 4 dead and 37 injured, with the total destruction of 10 buildings including several hotels. Many people fled from the costal area in fear of a Tsunami. An initial warning was issued, indicating a tsunami had been generated (based on gauge readings of sea level changes), the threat however was to the local area around the epicentre and only over a two hour period, there was no threat to other coastal areas in the pacific. The area has been subjected to 19 aftershocks of between M4.3 and M6.0 since.

Happy New year.... upload from PAUL stopped on Dec 22 after 12:00 UT, as did Snagit, I assumed either a time out glitch / power cut/server glitch, after Geoffs' posting I e-mailed iris, have had no reply but upload now seems to be working since 00:00 on 29th Dec.

Merry Christmas all....

 

I've not been successful with ftp uploads to IRIS, for at least a week, - does anyone know if the site is down for any especial reason ?

 

 

Tuesday 16/12/08  05:20:01 UT Sweden M 4.3

    0812160519PAUL.sac

Interesting reading comments on EMSC site. http://www.emsc-csem.org/index.php?page=current&sub=recent&evt=20081216_SWEDEN like the UK sizeable quakes are few and far between.

The M 5.3 earthquake in Southern Italy on wed 17/12/08 was at a depth 0f 275Km, so no clear signal.

Thursday's earthquake of the coast of Valparaiso, Chile 21:19:23 UT M 6.3 at a distance of 104.33 degrees placed the UK in the seismic wave shadow, again no clear signal.

Friday 19/12/08 08:31:51 UT M 5.9 Northern Mid-Atlantic ridge.

    0812190831PAUL.sac

Saturday 20/12/08 10:29:22 UT M6.5 off the East coast of Honshu Island , Japan.

    0812201029PAUL.sac

there were no reports of damage or any casualties, no Tsunami warning was issued.There were later aftershocks of M 5.1 (10:48 UT) and M 5.3 (12:22 UT)

 

The White Rose Grid iRODS Evaluation and Demonstrator Project This project will provide an in-depth evaluation and demonstration of the iRODS system, assessing its capabilities and role within a distributed data management scheme and complex virtual organisation driven by real-world requirements from the CARMEN e-Science project. Distributed data management issues are still a major challenge in addressing the ubiquity and usability of Grid systems, particularly within the context of complex virtual organisations (VO) where flexible security models and fine -grained role based access are a pre-requisite. The Storage Request Broker (SRB) software from SDSC has established itself as one of the leading Grid middleware applications to support the management of highly distributed large scale datasets for science applications. SRB provides the capability to virtualise distributed datasets, and to provide standardised access to a broad range of underlying storage technologies, spanning flat file systems through to database servers and tape archiving systems. Through the use of SRB, end-users are freed from concerns about the location of data and determining the correct procedures to recall or transfer data to their local or host compute environment. SRB abstracts these challenging aspects of distributed data management away from the end-user, and provides a simplified and uniform way to recall data via indexing systems (metacatalogs) which keep a logical mapping of the underlying distributed data. SRB has been widely adopted within large-scale Grid applications, particularly in the science communities, and provides the data management backbone for the National Grid Service (NGS). However, SRB does have limitations particularly in regard to integration with complex VO’s. These have been recognised by the developers of SRB at SDSC and a new version, iRODS, has recently been released to address the short-comings within SRB. Many of the limitations within SRB relate to the metadata schemes used to describe and annotate the data collections. In many cases these metadata mechanisms are too restrictive and inflexible to support complex meta-data schemes for complex role-based Grid systems. iRODS is dowloadable at release 1.1, and as part of the objectives of the JISC e-infrastructure imitative, this project will assess the impact that the new features and functions within iRODS will have on the UK e-Science community, and assess its potential for deployment within the NGS. [Note that the current iREAD demonstration uses an iRODS pre-release of 1.2 kindly provided by UCSD.]

This is a paper describing research undertaken by Clemson University exploring thought processes and problem solving. The paper describes the use of the Bloom taxonomy to understand the cognitive processes for computer scientists solving a data structure problem. Understanding this process is a key part of teaching, training and evan enabling machinie learning.

The paper provides a good introduction, overview and description of related work. In the concluding remarks it is acknowledged by the researchers that Bloom's taxonomy is difficult to use for the classification of cognitive processes.

The results show timelines for the Bloom classification contrasting the least successful and the most successful these amazing results would need to be supported by the provision of a confidence level. As the authors point out the small number of transcripts and the number of problems make it difficult to provide general characterisations.

The results of the analysis indicate the insight that has been gained into these processes. Amongst these ideas is the conclusion that successful problem solvers move more frequently between the different cognitive processes. It also lends support to  the idea that when we become stuck with solving a problem it is best to leave the problem and return at a later time. The research methodology identified here will find it difficult to quantify this technique.

Two areas in common with the White Rose Grid are as follows.

1. Using analysis techniques of the CARMEN [6] project to classify cognitive processes.
2. Automation of analysis techniques using structured Transcriptions and Information Extraction work undertaken at Sheffield [5]

Recommendations

1. In the methodology quantify how much effort undertaken by investigators to transcribe and classify the trannscripts.
2. Add a suitable legend to figure 1, make this clearer.
3. Identify candidate methods for improving the analysis work.

Links

1. Using Bloom’s Taxonomy To Code Verbal Protocols of Students Solving a Data Structure Problem
2. Wikipedia article on Taxonomy of educational objectives
3. Article on Bloom's taxonomy
4. Writing learning objectives using blooms taxonomy
5. Large vocabulary speech recognition systems and their applications
6. The CARMEN project
7. Research Methods: Verbal Protocols

A friend I walk with is keen on micronavigation his skill with map and compass is a good match for anyone wielding a GPS. This dependency on the earths magnetic field and our need to "correct for magnetic variation" makes me inquisitive about the nature of the earths magnetic field. As illustrated by the links below it comes as no surprise that a vast amount of intellectual effort has been expended in understanding geomagnetism since the early days of William Gilbert (1600) [2] upto modern day MHD computations modelling the geodynamo [1].

I have investigated a simple model of the earths magnetic field based on the idea that the earths magnetic field may be represented by a single current loop. We use numerical integration with the Biot-Savart law.

• Radius of the current loop is 4000km
• Loop carries a current of 1500MA

The following scilab script computes the magnetic field due to a current loop over a 22x22x22 region of total size 11R_e where R_e is the radius of the earth (R_e=6371km).Such a crrent loop is illustrated below.

For each computed field point the Biot Savart law is used to compute the field due to the loop, the numerical integration over the current elements is performed using Simpsons rule. The scilab script to perform this computation is linked below. The script requires a function routine to compute the simpson rule integration, these are contained in the zip file geomagresources.zip. The resources file also contains the net file used to visualise the results with IBM data explorer.

• Scilab script
• Resources

Results calculated using the scilab model and using the bfield2.net data explorer network are shown below.

The scilab script file generates general data scriptions that may be read by IBM data explorer. Using IBM data explorer to run the visual program bfield2.net we may view streamlines representing the magnetic field lines and indivdual magnetic field vectors at each spatial location. The visualisation has a control panel labelled controls that may be used to explore these different aspects of the data set. The results have been compared to the results generated using geomagnetic models provided by the geophysical data centre [7] and are representative within at least an order of magnitude. MHD models of the geodynamo enable an understanding of palaeomagnetism and the evolution of the earths mgnetic field. Results calculated using the MHD geomagnetic dynamo are shown below [1].

In 1838 the German mathematician and magnetician Frederick Gauss developed a method of representing the magnetic field in terms of a converging series of spherical harmonics, whose terms were functions of latitude, longitude and radial distance from the centre of the earth [5]. There exist a wide range of techniques for the computation of magnetic fields, this is important in a wide range of medical, scientific and technological disciplines. An interesting method is one that uses an expansion of spherical harmonics in reciprocal space [9].

In the final blog entry in this series of three we will investigate charged particle motion in the earths magnetic field.

Links

1. Geodynamo simulations using MHD
2. De magnete by William Gilbert (1600)
3. The geodynamo
4. Magnetic field of a current loop
5. Gauss spherical harmonic model for representing the geomagnetic field
6. Geophysical data centre- Geomagnetism
7. Geophysical data centre- Geomagnetic models and software
8. Numerical integration techniques for computing magnetic fields
9. Calculating magnetic field using semi analytical methods - reciprocal space expansion
10. IBM Data Explorer
11. Scilab