Stations and data

Overview

A network of shared scientific observatories across Africa is of fundamental importance to achieving a tightly integrated training and research programme for science capacity building. The network of observatories, linked through common instrumentation, data access, and operation, form a “shared” facility and as such provide an important means of building science community. Data from the observatories provide the underpinning for much of the science supported by AfricaArray. Some of the observatories are permanent, while others are installed and operated on a temporary basis.

The scientific observatories are built around broadband seismic stations for recording earthquakes. The reason for this is because the initial focus of AfricaArray was in geophysics.  The goal during the first phase of AfricaArray (2005-2007) was to establish a network of 20 to 30 permanent observatories spanning much of southern and eastern Africa. The placement of permanent observatories in many countries was governed by the location of existing seismic stations. Seismic equipment at many of these stations has been upgraded, the data have been formatted uniformly and archived, and access to the data has been streamlined.  During the second phase of AfricaArray (2008-2010), the network of permanent observatories was expanded into other parts of Africa, and starting in August, 2010, many of the observatories are being equipped with GPS receivers and automated weather stations.

Seismic Data Access

Seismic Data Access and Availability (new policy beginning February 2011)

Seismic data from the AfricaArray observatories are being archived and distributed by the IRIS Data Management Center under the network code AF. The data can be viewed at: http://www.iris.edu/mda/AF and can be obtained using standard data request tools at IRIS.

Beginning February 2011, all data for the following stations are open immediately:

SHAI, KUKU, IFE, YNDE, AAUS, TEBE, NBI, RUSH, GETA, DODT, MBEY, MTVE, MZM, ZOMB, LBB, TETE, TEZI, RUDU, WIN, POGA, SOE, SVMA, SKRH

For the remaining stations, the data are openly available after three years. The first open release was in October 2009 for data collected in 2005 and 2006 .Data collected in 2007 was released in October 2010. In-country network operators can release data from their stations to anyone during the three year holding period.

Before archiving data from some stations, it must first be processed for timing corrections and reformatted. Therefore, for some stations, there is a lag between when data are collected and made available at IRIS.

GPS & Weather Data Access

GPS and Weather Data Access and Availability

GPS and weather data from the AfricaArray observatories are being archived and distributed by the UNAVCO Data Management Facility Data are downloaded every few months from the observatories, and the data become available as soon as they reach the UNVACO archive. The first observatories were equipped with GPS receivers and automated weather stations in August 2010. Data from 2010 is now available.

The data can be obtained by going to: AfricaArray/UNAVCO Data Archive

Permanent Observations

Permanent Observatories (last updated 10/2010)

The map below shows the current distribution of AfricaArray seismic stations. Data for AfricaArray stations are being archived at the Iris Data Management Center. Information about each station can be found at http://www.iris.edu/gmap/AF. GPS and weather data are archived at the UNAVCO Data Management Facility.

Temporary Observations

The purpose of temporary observatories is to provide higher resolution data for studying scientific targets that cannot be well imaged using data from the permanent observatories. The temporary observatories can include one or more kinds of sensors. The map below shows temporary networks of broadband seismic stations operating between 2007 and 2010.

Technical Training Programme

Sponsor of Technical Training Course

The technical training of personnel to operate and maintain seismic equipment for AfricaArray is performed by the Council for Geoscience (CGS) both at the CGS’s offices in Pretoria and in the field at selected AfricaArray stations. The Council for Geoscience has been training station operators from many African countries over the past few years in the topics outlined below. Certificates are issued when the station operators complete the training course.

The majority of the course will consist of a series of practical exercises, during which the students may obtain hands-on training and thus familiarize themselves with the equipment.

Objectives of the Training Course

The objectives of the technical training course is to present both a theoretical and practical introduction to the seismological instrumentation that will be used at AfricaArray stations.

Proposed Course Description

The course will be structured in such a way as to expose the student to both the theoretical and practical aspects of a seismological station, such as:

  • Site preparation
  • Instrumentation
  • Installation
  • Calibration
  • Operation

These aspects will be covered by the following subjects:

  • Site selection
  • Vault construction
  • Computer literacy
  • Electronics
  • A/D converters
  • Seismic sensors
  • Seismic noise reduction
  • Lightning protection
  • Data loggers
  • Communication equipment/software
  • Calibration equipment
  • Backup devices
  • Data acquisition software

Inquiries

For more information about the technical training programme and how to apply please contact Michelle Grobbelaar at michelle@geoscience.org.za.