by Peter J. Wyllie
President, International Union of Geodesy and Geophysics
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Our Australian hosts, Chairman Pearman, Presidents Duce and Shannon, Secretaries-General List and Camfield, ladies and gentlemen:
It gives me great pleasure to have the opportunity to open this Joint Assembly of the International Association of Meteorology and Atmospheric Sciences, and the International Association for the Physical Sciences of the Oceans.
I bring three messages:
(1) to deliver greetings from IUGG, the International Union of Geodesy and Geophysics, which is your Union,
(2) to offer my compliments to you for arranging a Joint Assembly involving not just 2 but 4 Associations, along with my best wishes for a highly successful Assembly, and
(3) to invite you to attend the XXIInd General Assembly of the IUGG in July 1999, in the old country, England.
Knowing that many scientists come to Conferences such as this without realizing that their attendance has made them members of the IUGG, I thought it would be appropriate to cover three topics:
(1) to outline the structure of IUGG and the position of IAMAS and IAPSO within the scientific framework of the Union, then
(2) to explore the involvement of IAMAS and IAPSO with global processes, and with the other Associations, before finally
(3) considering some priorities for the next century.
IUGG deals with the magnetic properties of the Earth's core, with the physical and chemical structure of the Earth's interior and crust, with the fluid envelopes of water and atmosphere, and with the magnetosphere and so into space.
IUGG is a Union of seven International Associations, which are listed here, The International Associations of:
What does the Union do?
IUGG collects financial contributions from about 80 Member Countries, and redistributes that income among the 7 Associations. IUGG is your connection to ICSU, the International Council of Scientific Unions. IUGG is your union, and it can be successful only as long as you and the other Associations work together. The most visible product of the Union is the quadrennial General Assembly, at which all disciplines are brought together in a rather frantic international bazaar. These meetings are hated by many for their size, but sufficiently stimulating that many young scientists once invited to give a paper at an IUGG General Assembly keep coming back through maturity, as long as their research grants hold up.
Why do we bother with a Union and its cumbersome Assemblies? There are two obvious reasons:
(1) We are concerned with global problems and processes. Therefore, we all benefit from the involvement and collaboration of scientists in countries around the world.
(2) All of the processes we investigate are interconnected.
The scope of the science covered by IUGG can be illustrated by this cross-section through the Earth (Figure 1). Each Association has its own domain, but the boundaries between them are artificial. Global processes are undisciplined - they pay no attention to the artificial disciplinary subjects and Associations which our culture has built up. Therefore, many processes can be explored only through collaboration with scientists in other Associations.
During my years at the University of Chicago, I learned from Joe Pedlosky that Geophysical Fluid Dynamics was the common link between the solid and fluid Earth, and that all of these motions are controlled by the same physical equations. Much later, at Caltech, I saw graduate student Paul Tackley use those equations to calculate by computer this picture of mantle convection - the Global Circulation Model for the Earth's interior.
IAMAS AND IAPSO are concerned with the fluid envelopes around the solid Earth. This picture of Copacabana Beach, Rio de Janeiro, famous for its free-spirited swim-wear, was taken during the wrong season - there is not one person on the beach. However, it is a reminder that the stormy ocean reservoir (IAPSO) is transferred to the land by the clouds looming above the waves (IAMAS). IAHS depends for its freshwater on IAPSO and IAMAS. The sand, eroded first from the land by fresh water, and then rolled along the beach by ocean water, may one day become a sandstone aquifer (IAHS).
IUGG and its Associations have much to offer in basic research which can help us obtain a better understanding of Climate Change. Several Associations are strongly involved. Interactions between IAHS, IAMAS and IAPSO are planned for this Joint Assembly and IAVCEI also shares a Symposium. Science News warns us on its cover page that ".. the World Warms". But how sure are we that the world is warming? The cover of the book by Imbrie and Imbrie reminds us that we are currently within an ice age. I hope that the members of IAMAS and IAPSO are really sure which way we are going before we take corrective action. If global warming is really an established fact, let us remember that it is occurring within an Ice Age which has already experienced many major climatic cycles without any intervention by or influence of humankind. The geological record confirms that global change has been operating through at least 4 billion years.
I tell my students of petrology that all good things come from the Earth's mantle, and they are delivered by volcanoes. IAVCEI is the direct link between the Earth's internal and external engines. Mt. St. Helens erupting provides an obvious demonstration of material additions to the atmosphere, and I do not need to comment on the effect of such additions on climate. Material is added to the ocean via circulation of ocean water into the crust in regions heated by volcanic activity. This slide is a sketch of a "chimney" formed on the ocean floor from a submarine hydrothermal vent, representing one of the most dramatic exchanges between the fluid envelopes and the solid earth. The circulating ocean water experiences enormous chemical exchanges with the basalt of the ocean floor, and as it emerges in the hot springs the chilling causes immediate precipitation of dissolved material. The deposits include metallic sulfide minerals which will become ore deposits as they are later incorporated into continental mountain ranges, and amazing oases of life without photosynthesis.
In subduction zones, where plates of the Earth's solid upper boundary layer converge, huge quantities of H2O and CO2 trapped from the ocean are carried down to depths of at least 100 km, and perhaps deeper than 670 km. Some seismologists and geochemists (IASPEI, IACVEI) write in terms of 10 ocean masses of H2O stored within the Earth's deep mantle. Dissociation reactions at high pressures and temperatures release H2O and CO2 which becomes involved with volcanic processes, and the gases reach the surface again through volcanic eruptions.
Mount Rainier is a beautiful mountain looming over Seattle. It is also a rotten volcano, whose fate depends on IAPSO and IAMAS, as well as IAVCEI. My magma (IAVCEI) has been corroding the inside of the mountain through about 2,000 years since the last eruption. Precipitation from IAMAS has been attacking the outside of the mountain. Eventually the walls must break, and an eruption powered by subducted Pacific Ocean water (IAPSO) will produce much devastation: a plume of volcanic ash rising into the stratosphere, and possibly complete explosion of the mountain like that which resulted in Crater Lake, and Santorini. A local volcanic disaster like this could have global consequences, not only through climatic change, but in terms of the economy. Many of us wrote our abstracts using Microsoftware, and many flew here in Boeing aircraft. The headquarters of both companies are within striking distance of Mount Rainier, but I should add that the odds of these companies being stricken even if there is an eruption is very low.
What are our scientific priorities as we enter the next century? They must be based on beautiful science. We have plenty of intriguing scientific problems to arouse our curiosity. But we must give equal weight to societal problems, the challenges of sustaining sufficient resources, of coping with natural hazards as humanity progressively covers the surface of the Earth, and of adjusting to inevitable environmental and climatic changes. As we look at the cover of "Time" magazine which shows the globe of "endangered Earth" wrapped in cellophane and tied with string, we know that it is essential that we obtain a better understanding of how we as a society are affecting the Earth cycles, and contributing to environmental change, before we do irreparable damage and rupture the delicate film of fluids and soil on which we depend. If that happens, we will not be able to enjoy the luxury of conducting pure science to satisfy our curiosities. So, after you have solved all the problems in the fluid sciences during this Assembly, do join the solid folk at the great international "science bazaar", the next IUGG General Assembly in July 1999, and solve the global problems which link the fluid and solid Earth.
I now declare this Joint Assembly -- to be OPEN!
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