Introduction

The contribution to seismology of the Society of Jesus as an institution through its colleges and universities and of its members as individual scientists forms an important chapter of the history of this science, especially in the early years of its development.  However, this is not widely known.  Recently many Jesuit seismographic stations have been closed and the number of Jesuits actually working in seismology has been greatly reduced.  To a certain extent, it can be said that this is a chapter which is practically finished.  Jesuits' interests have moved into other directions and it is not likely that seismology will become again an important aspect of their work as it was in the past.

A series of circumstances and interests involved Jesuits in the development of this relative new science from its inception.  The interest, certainly, was consonant with the tradition of Jesuits in science dating from the 16th century and developed out of their work in colleges and universities.  The character of seismology as a public service to mitigate the destructive effects of earthquakes was another influential factor.
 

Especially in undeveloped countries, Jesuits were in many instances the first to install seismographic stations and to carry out seismicity and seismic risk studies.  Two trends may be distinguished in this involvement of Jesuits in seismology.  In the United States emphasis was on the cooperation of Jesuit institutions in the establishment of a network of seismographic stations.  In other countries, especially in mission lands, the movement developed out of the activity in individual observatories.

Jesuit Seismographic Stations
The first seismographics were installed by Jesuits in about 1868 in the Observatory of Manila.  In total 37 seismographic stations were installed and maintained by Jesuits throughout the world.  Distribution by continents is as follows: Europe 6, Asia 4, Africa 1, Australia 1, North America 18 and South America 7.  Most of these stations were created before 1920 and many ceased operations in the 1960s and 1970s.  At present there are only eight working regularly.  Initially, in the beginning of the century, the preferred instruments were Wiechert and Mainka mechanical seismographs, towards 1930 Galitzin-Wilip electromagnetic seismographs were installed and later Sprengnether and Benioff instruments.  In 1962 seven stations became part of the 125 global network of WWSSN (World Wide Standard Seismographic Network) stations supported by the U.S. Government.

The Jesuit Seismological Association
The history of Jesuits' work in seismology in the United States is linked to the Jesuit Seismological Association.  In 1908, F.L. Odenbach, Professor in John Carrol University, Cleveland, Ohio, conceived the notion that the system of Jesuits' colleges and universities scattered throughout the United States offered an opportunity to establish a network of seismographic stations.  Fr. Odenbach thought that such a network could contribute significant data to the study of earthquakes.  Odenbach sold the presidents of the colleges and the American Jesuit provincials on the idea.  In 1909 sixteen identical horizontal Wiechert seismographs of 80kg mass were purchased in Germany and were distributed to fifteen colleges in the United States and one in Canada.  These stations formed the Jesuit Seismological Service.  Individual stations would process their seismograms and send the data to the Central Station in Cleveland.  These would then be sent to the International Seismological Centre in Strasbourg.  This was in effect the first seismological network established of continental scale with uniform instrumentation.

In 1925, J.B. Macelwane dedicated his first efforts to revitalize the Jesuit seismographic network.  The stations were newly reorganized into the Jesuit Seismological Association with 14 member stations and Saint Louis University as the Central Station.  The Central Station assumed the responsibility of collecting data from member stations and from around the world and of locating earthquake epicenters and publishing them to the worldwide seismological community.  The JSA continued this service until the early 1960s, when it was discontinued not to duplicate the determinations done by United States and other international agencies.  Most of the JSA seismographic stations continued regular operation until relatively recent time.

Jesuit Seismologists
From 1868, approximate date of the installation of the first seismograph in Manila, to the present, many Jesuits have dedicated their time and efforts to seismology.  In this short note it is hardly possible to do more than mention a few of the most important of them.  The first Jesuit to be mentioned is F. Faura who published a study about the destructive Philippines earthquakes of 1880 recorded by the instruments of the Observatory of Manila.  Faura continued his interest in seismology improving the seismological instrumentation of the Observatory and publishing a seismological bulletin.  Two Jesuits contributed very early to the study of the seismicity and seismotectonics of Philippines and Spain.  M. Saderra-Masó dedicated himself to the study of the seismicity of Philippines interpreting it in terms of seismotectonic lines and relating it to the geologic structure in the archipelago.  M. Sanchez Navarro-Neumann, director of the Observatory of Cartuja, Spain, compiled the first modern earthquake catalogue of Spain and published numerous studies on the seismicity of that region.

The most renowned Jesuit seismologist was without doubt J.B. Macelwane.  Macelwane obtained his doctor degree in the University of California, Berkeley, in 1925, with the first thesis in seismology in the United States.  In 1925 he became the first director of the Department of Geophysics in Saint Louis University and reorganized the Jesuit Seismological Association.  Travel times of seismic waves, the constitution of the interior of the Earth, and the nature of microseisms and their relation to atmospheric storms were a few of the topics of his research papers.  In 1936 he published the first textbook in seismology in America.  He was President of the Seismological Society of America and of the American Geophysical Union, and elected to the national Academy of Sciences.  In 1962 the American geophysical Union created a medal in his honour for recognition of significant contribution to the geophysical sciences by a young scientist of outstanding ability.