PROJECT'S TITLE: SEISMOLOGY AT SCHOOLS

KNOWLEDGE FIELD: EXACT SCIENCES

SUPERVISOR: George Sand Leão Araújo de França

The Project

Seismology is a science which High-School students are not very much familiarized with. However, we can surely improve on the awareness of Seismology, since this science has a far more vast field, which encompasses the study of the generation, propagation and the recording of elastic waves (seismic) that may observed on the surface of the Earth and also the study on the sources that produce them. A variety of phenomena (natural or artificial) may give rise to the propagation of seismic waves, but only a few of them are regarded as seisms. We consider as seisms all the mechanisms which produce elastic-waves, whose origin can be determined in terms of space and in time. In this comprehensive concept we ruled out only the diffuse sources of vibration, usually analyzed according to their seismic noise.

Seisms tend to have a bad reputation, since they are referred to only when there is some kind of disaster, which likely results in casualties. However, the true concept of this kind of seism is linked to the sudden movement in geological-fault areas and is called tectonic seisms. The term “seism” associated here to the cause of the phenomenon is also used currently to represent the ground vibration that is felt or just recorded at any point of the Earth's surface. The ambiguity of the term “seism” is lessened if we separate seisms into two definition groups: earthquake and land tremors (seismic shocks). Brazilian seismology scientists call by earthquakes the damage-resulting seisms whereas the small seisms are simply called “seismic tremble”.

Seismology is a little-approached theme in High-School Exact Sciences' subjects and basic education due to its not being a part of our history. But in 2004, a major earthquake produced huge waves (Tsunami) and caused the death of approximately 283 thousand people (USGS, 2007). This led to some kind of curiosity on the part of teachers and students, generally speaking. Thus, experimental activities related to seismology can be done with a an easier understanding of this science.

In order to perform experiences on seismology, first it is necessary to record the seisms and, if possible, for schools to have at their disposal the appropriate equipment. Basically, the following items are required: a sensor, an acquisition system and a computer, which performs the analysis and interpretation of the recordings. This equipment is neither easily purchased nor is it easily operated. Therefore, we are going to begin our research from the elaboration and creation of a low-cost sensor (seismometer), which can be assembled everywhere.

Following examples from analogous experiences both in the United States and Portugal, this project must also get the High-School teachers of Physics involved in the construction of seismic sensors and, in the future, in the assembly of an acquisition system. Seismology is directly related with Geology and Geophysics when it comes to the understanding of the land tremors-producing phenomena, but also Physics and Chemistry, since they provide the seismologist with the necessary knowledge to have an idea about Earth's deepest structures. Seismology is a wide-raging multi-discipline field that contributes to the study of our ever-dynamic planet. Thus, Seismology is a global science in the sense that seisms do not “respect boundaries” and we must make our efforts bearing this in mind. For this reason, Seismology is nowadays an excellent example of the use of the Internet for the spreading of data and information. These aspects can be explored within the classroom, using computers as a resource, and with the contribution of teachers and computers, which might be useful in future projects.

Concomitantly to the sensor's elaboration and assembly, the scholarship student will become involved in the programs for analysis, which allow the observatory's main tasks to be effectively performed, such as: the identification of the seismic stages, the determination of the epicentral distance and the magnitude's calculations.

Bibliographical References

Walker, J., 1979, The Amateur Scientist: How to Build a Simple Seismograph to Record Earthquake Waves at Home, Scientific American, v. 241(1), 152-161.

Matias, L. e Torres, L., 2000. O ensino experimental da Sismologia, Comunicar Ciência, Ano I, nº4, 4-5.

Teixeira , W.; Toledo, M.C.M.; Fairchild, T.M.; Taioli, F., 2000, Decifrando a Terra. Universidade de São Paulo, São Paulo, Brasil, 558pp http://earthquake.usgs.gov/regional/world/most_destructive.php, 2007. USGS.