Eos, Vol. 72, No. 21, May 21, 1991

tween the creation of heterogeneities and the Physics and Chemistry efficiency of convection in homogenizing the mantle on different scales (Richter et at., 1982; Hoffman and McKenzie, 1985]. One of Mantle Plumes explanation for the persistence of heteroge- neities is that they are continuously forming, PAGES 236-237 so there is always a steady-state concentra­ tion of them in the mantle. Identifiable mechanisms for the introduction of heteroge­ Donald J. DePaolo, Edward M. Stolper, and Donald M. Thomas neities include subduction of oceanic crust, including sediment derived from continents, subduction of continental lithosphere, and Hot spot volcanic chains are a funda­ structure of oceanic volcanos, and a number creation of "depleted zones" in the mantle in mental feature of the Earth's crust, but their of other geophysical and geochemical prob­ regions from which magma has recently origins are still poorly understood [ Okal and lems. Drill coring is an effective means of been extracted. An alternative view is that Batiza, 1987]. The Hawaiian-Emperor vol­ addressing these problems because the tar­ large parts of the mantle are permanently canic chain, which dominates the topogra­ gets-the lava accumulations of the large separated from each other, the prevailing phy of the central Pacific ocean floor, is the Hawaiian shield volcanos-are nearly hori­ model being that the mantle is chemically best developed and most intensely studied zontal subsurface features. The information layered. At one time, these models were of the known hot spot tracks. It continues to accessible through drilling is unlikely to be­ considered in opposition to one another (Zindler et at., 1982], but they have since be one of the world's most important field come available otherwise; hence it appears laboratories for the study of igneous pro­ necessary to employ drilling to effectively been recognized to be complementary (Zin­ dler et at., 1984]. cesses, plate movements, mantle convection, address the scientific problems. structure, geochemical evolution, and the This article describes the primary scien­ Within this general framework, the ques­ properties of the lithosphere. tific basis for the proposed project-elucida­ tion of the nature of hot spots plays a central role. A common line of argument follows Despite continued effort, fundamental tion of the physics and chemistry of the Ha­ from the observation that hot spots seem to questions regarding the composition, struc­ waiian mantle plume on the time scale of a ture, and evolution of Hawaiian volcanos single volcano (about 106 years). be fixed, or at least slowly moving in rela- and their magma sources remain unan­ swered. This is largely due to the fact that b only lavas representing the late stages in the evolution of the volcanos can be sampled at Origin and Chemistry of Mantle the surface. Most of the internal structure of Plumes the volcanos and evidence of their growth The plate tectonic revolution and the history and geochemical evolution are hid­ concurrent exploration of other solar system den from view. The most deeply eroded vol­ bodies caused a profound change in the way canos are exposed only to depths of a kilo­ Earth evolution and structure are viewed. In meter or so, whereas the volcanos rise some many ways, the shifts in the basic paradigms 5-15 km above the old ocean floor (Moore, revolve around the central theme that con­ LOWER MANTLE More primitive ? 1987]. vection in the Earth's interior is probably the More homogeneous ? In late 1986, in recognition of the scien­ single most important process determining tific value of observing the deep interiors of the evolution of the Earth. Study of plate tec­ Hawaiian volcanos, a group of Earth scien­ tonics led to the realization that large-scale tists submitted a proposal to the NSF-spon­ movements are taking place in the Earth's sored drilling consortium DOSECC (Deep mantle, which brought into focus the need Observation and Sampling of the Earth's to understand the properties of mantle mate­ Continental Crust) to drill and core a vol­ rials, convection itself, and the relation of cano to retrieve and study a more complete mantle dynamics to seismic structure, the stratigraphic sequence of its lavas. Following geopotential fields, the figure of the Earth, the reorganization of the drilling programs, and the evolution of continents. this proposal was submitted to the Continen­ Since direct study of the mantle is in tal Lithosphere Program of the National Sci­ most cases impossible, indirect means must Fig. 1. Earth models and their association ence Foundation in 1988 and again in 1989. be employed. Such means include global with the issues of the sources and dynamics The proposed Hawaiian Scientific Drilling heat flow studies, studies of the geoid, and of mantle plumes. The upper mantle is Project (HSDP) is aimed primarily at improv­ seismic studies combined with high-pressure known to be depleted in magmaphile and ing understanding of the structure and dy­ material properties research. These ap­ volatile elements and to be very heteroge­ namics of the mantle, particularly with re­ proaches study the mantle as it is currently. neous. The lower mantle may be more prim­ gard to the origin of mantle plumes and their Geochemical studies of mantle-derived mate­ itive (less depleted) and less heterogeneous. interaction with the lithosphere and shallow rials have a special role in that they provide The lowermost mantle might contain primi­ asthenosphere. The proposed studies would insight both about the existing structure and tive material, mantle material that has re­ also provide unique data on the physics and composition as well as time-dependent infor­ acted with the core, or subducted slab (recy­ chemistry of magma generation, the internal mation, such as residence times and dis­ cled) material. The 670-km seismic persal times. The time dimension is accessi­ discontinuity may be a thermal boundary ble through the study of isotopic variations, layer between two convecting systems, or and the most useful vehicles are basaltic simply a phase-change boundary. Plumes lavas that bring the information to the Earth's Donald J. DePaolo, Center for Isotope Geochemis­ might originate at thermal boundary layers try, Department of Geology and Geophysics, Uni­ surface from source regions in the mantle. at (a) the 670-km level, (b) the core-mantle versity of California, Earth Sciences Division, Over the past 2 decades, isotopic studies boundary, or (c) within the lower mantle. Lawrence Berkeley Laboratory, Berkeley, CA 94720; of oceanic basalts have shown that the man­ The erupted lava compositions are affected Edward M. Stolper, Division of Geological and tle contains diverse materials [e.g., Zindler not only by the source of the plume, but also Planetary Sciences, California Institute of Technol­ by the amount of entrainment (in upper and ogy, Mail Code 170-25, Pasadena, CA 91125; Don­ and Hart, 1986]. Convection should eventu­ ald M. Thomas, Hawaii Institute of Geophysics, ally make heterogeneities disappear, so their lower mantle) and the amount of assimila­ University of Hawaii, Honolulu, HI 96822. existence is a measure of the balance be- tion of lithosphere.

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tion to the plates, suggesting a deep source pretation of seismic velocities in the deep lavas, and then to transitional tholeiitic la­ (Morgan, 1971]. In addition, some of the Earth, are thus affected. If the lower parts of vas, in the sense that the isotopic composi­ geochemical properties of lavas associated the mantle are not well degassed, it impacts tions look less like those of MORB and more with hot spots suggest that the mantle mate­ theories of the origin of the atmosphere and like those of primitive mantle material (eNd rial from which they are derived is different oceans (e.g., Hart eta/., 1979]. If only the = 0). This has been interpreted as evidence and more primitive (that is, more similar to upper mantle has been involved in the for­ for two major mantle sources for the lavas. the original bulk composition of the Earth) mation of the continents, it affects the way One source, the one with the MORB-like sig­ than what is typical of the upper mantle as we view the composition of the continents nature, is interpreted to be the oceanic litho­ indicated by MORB (mid-ocean ridge ba­ and oceans and how their compositions sphere. The other source is presumably a salts) (e.g., Schilling, 1973; Chen and Frey, have changed with time (DePaolo, 1980]. deeply-sourced mantle plume. There is a 1985]. This mantle material is also different The interiors of Hawaiian volcanos may suggestion that farther down in the lava se­ in such a way that it may not be explainable carry particularly diagnostic information for quence, in the "middle" of the main "tholei­ in terms of recycled oceanic or continental assessing the ultimate origin and nature of itic" stage, the lavas may have isotopic com­ crust (Kurz eta/., 1982; Hofmann and White, mantle plumes. This statement stems from positions that are different from the MORB­ 1982]. There has followed the hypothesis the observation that erosion exposes lavas type values. It is noteworthy that the study of that hot spots represent "plumes" of chemi­ that represent only the end stages of the vol­ Chen and Frey ( 1985], which was an impor­ cally and isotopically special material from canos' lifetime, and that there are trends in tant advance from previous work, was done deep in the mantle. composition in these late-stage lavas that on drill-core material. If plumes are chemically and isotopically suggest that the interiors of the volcanos are Two other observations are important. different from normal upper mantle material, different. Even in the most deeply eroded volcanos, only about 10-15% of the history Hawaiian lavas, including those from Loihi the easiest explanation is large-scale layer­ 3 ing, with inhibited exchange of material by of a volcano can be observed. The end seamount, have very high HefHe ratios convection between the layers (see Figure stages of most volcanos involve a transition (Lupton and Craig, 1975; Kurz eta/., 1982; 1). The question of layering or otherwise from tholeiitic lavas to alkalic lavas. The Staudigel et a/., 1984], which indicate that isolated reservoirs is one of the fundamental long-standing model is that all the lavas the magmas come from mantle reservoirs questions about the Earth. The issue has from the inception of the volcano to the tran­ that are more primitive than the MORB reser­ many ramifications. For example, layered sition stage are tholeiitic (MacDonald and voir (Figure 2). Because of differences in convection tends to aid the Earth in retaining Katsura, 1964], but there are few direct ob­ concentrations in different reservoirs, the heat in comparison to whole mantle convec- servations to support this. Recent observa­ primitive He may be relatively less diluted by tion (Spohn and Schubert, 1982]. Thus an tions at Loihi (Moore et a/., 1982] and in the upper mar.tle material than are Nd and Sr. In addition, in the case of one eroded Hawai­ understanding of the thermal history of the submarine part of the Kilauea East Rift Zone in fact suggest that alkali basalt may be ian volcano, the Koolau shield of Oahu, Earth hinges on this question, as does our common throughout the lifetime of a vol­ there is a strong indication of the presence ability to extrapolate our knowledge of the cano.· of mantle material of substantially different current style of tectonics to the Earth's early A trend discovered by Chen and Frey composition (Figure 2a). The Koolau basalts history. ( 1985] suggests that the interiors of some of also have Hf and Pb isotopic compositions Layering of the mantle is only possible if the volcanos contain flows with geochemical that could be considered to be primitive the chemical differences of the layers are signatures different from the exposed flows. (Stille et a/., 1983]. The basalts of Oahu such as to make the lower layers more Figure 2a shows the Nd and Sr isotopic com­ show a relationship similar to that of the dense (e.g., Richter and McKenzie, 1981]. positions of Haleakala basalts. Among these Haleakala lavas in that the posterosional la­ Our understanding of the composition of the basalts there is a trend from posterosional vas (Honolulu series) have isotopic compo­ Earth, and thus of its origin, and the inter- alkalic lavas to the late-main-stage alkalic sitions approaching those of MORB, whereas

0.5134 R = 100 30 • Honolulu S.rtaa (Oahu) • Koolau Volcano (Oahu) Halaakala Volcano (Maul) 25 0.5132 (\~ 'f"'~0 ~~ + 10 E "C <~ ~ ....ca ...z ~o"' .,o ~ 1,~.. a: 20 Kilauea ~~ ~~ a: ~ ""6 ""6, Tfr.A "" - 0.5130 Q) :I: ~~-----Hualalai "C- 15 Bouvet . z ~ + 5 Q) V Reun1on (") ~ IA1-- ...... -:I: B ~ ~~ M 0.5128 .,~ 10 ~ • Mauna Loa Tristan da Cunha .0 •• ~6 MORB ~ ' f-Gough ~6 . 0 5 La Palma Jan Mayen "J I _;J 0.5126 0.702 0.703 0.704 0.705 .7025 .7030 .7035 .7040 .7045 .7050 B7sr ,assr a b 87sr,S6sr Fig. 2. (a) Nd and Sr isotopic ratios in lavas from Oahu and the lithospheric (or local asthenospheric) contributions to the magmas Haleakala volcano of Maui (data from Roden et al. {1984/ and Chen in the waning stages of the volcanos lifetime. The main stage is and Frey {1985/). Tholeiities (T and solid circles), erupted earlier, are generally hidden from view beneath the /ate-capping lavas. (b) He much more voluminous, and have isotopic ratios more like whole and Sr isotopic ratios of some oceanic basalts, showing that active Earth values (eNd = 0) than those of alkali basalts (A) erupted near Hawaiian volcanos contain He that is rich in 3He, which distin­ the end of the main stage of shield building, or nephelinites (solid guishes them from mid-ocean ridge basalt and many other oceanic squares), which were erupted well after the cessation of shield basalts. building. These data have been interpreted in terms of increasing

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the older tholeiites of the Koolau volcano the plume and thus represents a complex for determining (I) the nature of the mantle have isotopic compositions far removed magma source geochemically. The column sources of the magmas (for example, upper from those of MORB. represented by the plume "tail" is expected versus lower mantle; plume versus litho­ Of the known hot spots and hot spot to be a long-lived feature; a conduit through sphere/asthenosphere) and how they change tracks, Hawaii is the obvious place to at­ which hot, bouyant material from the deep with time; (2) the nature and temporal evolu­ tempt to further elucidate the nature of hot boundary layer "drains" to the near-surface tion of the melting and magma segregation spots. Continental localities are more com­ region of the mantle. processes in the mantle; and (3) the roles of plicated because of the potential for contam­ This model presents a relatively simple shallow versus deep magmatic processes in ination of the lavas by continental litho­ framework for understanding the nature of the generation of the lavas erupted at the sphere. Mid-ocean ridge localities can be magma sources in an active plume long after surface. With good age control, the rates of eliminated because upwelling at the ridges initiation, which is the case applicable to magma generation, changes in magma tends to dilute the plume signal. Of the re­ Hawaii. The structure proposed resembles source characteristics, and the role of shal­ maining ones, Hawaii is a much longer-lived that suggested by Schilling [19731 for the low magmatic processes can be determined, feature, much more is known about it, and it Iceland plume. This model raises several providing a unique characterization of hot is still active. questions. For example, how well does the spot magmatism. plume material arriving at the base of the Magma Genesis and lithosphere mix with the surrounding litho­ Acknowledgments Plume-Lithosphere Interactions spheric and sublithospheric mantle? How is such mixing related to magma generation Written contributions to the proposals rates and magma types? Is the flow in the from whiCh this summary was abstracted Since the importance of the relative fixity were provided by D. Clague (U.S. Geological of hot spot volcanism was realized, several plume conduit steady or are there variations with time? With regard to the last question, it Survey), G. B. Dalrymple (USGS), M. Garcia mechanisms have been proposed to explain (University of Hawaii), T. Henyey (University it. The most widely recognized of these is has also been suggested that plume flow of Southern California), D. P. Hill (USGS), P. the mantle "plume" hypothesis [e.g., Mor­ may be in the form of a train of diapirs Johnson (University of Washington), M. Kurz gan, 19711. Other models include one of a rather than a pipe [Schilling and Noe-Nyga­ propagating crack in the lithosphere [Jack­ ard, 1974; Olson and Singer, 19851. (Woods Hole Oceanographic Institution), J. son and Wright, 19701, shear melting with Models for the behavior of melt segregat­ Lockwood (USGS), J. G. Moore (USGS), F. M. thermal feedback [Shaw, 19731, and diapiric ing from flowing, partially molten regions of Richter (University of Chicago), G. P. L. upwelling along a line of structural weak­ the mantle are not yet well enough devel­ Walker (University of Hawaii), R. Wilkins ness !McDougall, 19711. Some of these mod­ oped to predict the details of the melting­ (University of Hawaii), and H. G. Wilshire els are applicable to mid-plate hot spots, but mixing-segregation processes at the plume­ (USGS). Support for a workshop and contin­ would be unlikely to explain hot spots that lithosphere conjunction Icf. Ribe and ued planning has come from DOSECC and occur at mid-ocean ridges. The plume hy­ Smooke, 1987; Richter, 1986; McKenzie and the Continental Dynamics Program of NSF. pothesis has also been considered as a Bickel, 19881. However, the geochemical­ mechanism for generating continental rifting. petrological time series that could be gener­ According to the "plume" hypothesis, ated from a continuous sampling of the vol­ References mantle material rises diapirically from an canic output of a volcano over most of its Chen, C. -Y., and F. A. Frey, Trace element and approximately fixed location deep in the lifetime could be one of the best approaches isotopic geochemistry of lavas from Haleakala mantle. As it nears the surface, the rising available for obtaining a phenomenological volcano, East Maui, Hawaii: Implications for the mantle material begins to melt in response basis for understanding these aspects of the origin of Hawaiian basalts, 1. Geophys. Res., 90, 8743, 1985. to decreasing pressure, and the liquid por­ physics of hot spots. Modern methods of DePaolo, D. J., Crustal growth and mantle evolu­ tion escapes upward and erupts on the trace element analysis, coupled with existing tion: Inferences from models of element trans­ growing volcano. Although the source of ris­ models for melt segregation, allow us to in­ port and Nd and Sr isotopes, Geochim. Cosmo­ ing diapirs is fixed, the oceanic lithosphere vert trace element compositions to deter­ chim. Acta, 44, 1185, 1980. Feigenson, M. D., and F. J. Spera, Dynamical is moving continuously. As a result, a linear mine parameters associated with the melting model for temporal variation in magma type and series of volcanos develops; active volca­ process such as the melt fraction attained eruption interval at Kohala volcano, Hawaii, Ge­ nism is limited to the region that currently and the depth of melting IFeigenson and ology, 9, 531 , 1981. overlies the fixed plume of rising mantle ma­ Spera, 19811. These parameters can only be Hart, R., J. Dymond, and L. Hogan, Preferential terial, but a sequence of inactive, progres­ obtained if one knows that the composition formation of the atmosphere-sialic crust system of the magma source is unchanging with from the upper mantle, Nature, 278, 156, 1979. sively older volcanic edifices that grew when Hoffman, N. R. A., and D.P. McKenzie, The de­ they previously sat astride the plume extends time and/or position. To constrain this, one struction of geochemical heterogeneities by dif­ away from the site of active volcanism in the must bring in isotope ratios, which can iden­ ferential fluid motion during mantle convection, direction of plate movement. In the case of tify the roles of different magma sources. In Geophys. 1. R. Astron. Soc., 82, 163, 1985. the Hawaiian-Emperor volcanic chain sitting Hawaii we have a special situation where we Hofmann, A. W., and W. M. White, Mantle plumes know already that there are two magma from oceanic crust, Earth Planet. Sci. Lett., 57, on the northwestward moving Pacific plate, 421' 1982. active volcanism is restricted to the south­ sources involved-plume and lithosphere/ Jackson, E. D., and T. L. Wright, Xenoliths in the eastern end of the chain, where there has asthenosphere-and that they have distinct Honolulu volcanic series, 1. Petrol., II, 405, been a source of magma for about 70 m.y. isotopic signatures. The Hawaiian hot spot 1970. Recent work has refined the plume thus represents a rich natural laboratory for Kurz, M.D., W. J. Jenkins, and S. R. Hart, Helium the study of fundamental planetary pro­ isotopic systematics of oceanic islands and model. Laboratory and theoretical models mantle heterogeneity, Nature, 297, 43, 1982. suggest that plumes originate from thermal/ cesses. Lupton, J. E., and H. Craig, Excess 3He in oceanic chemical boundary layers in the mantle or at basalts: Evidence for terrestrial primordial he­ the core-mantle boundary and consist of a Summary lium, Earth Planet. Sci. Lett., 26, 133, 1975. large-diameter "head" and a "tail" with a Macdonald, G. A., and T. Katsura, Chemical com­ much smaller diameter !Whitehead and The goal of the Hawaii Scientific drilling position of Hawaiian lavas, J. Petrol., 5, 82, 1964. McDougall, 1., Volcanic island chains and sea-floor Luther, 1975; Richards eta/., 19891. When project is to obtain a continuous sequence spreading, Nature Phys. Sci., 231, 141, 1971. the head reaches the melting zone at shal­ of lavas from a single Hawaiian volcano ex­ McKenzie, D.P., and M. J. Bickel, The volume and low depth in the mantle it produces a huge, tending from post-shield alkalic lavas back composition of melt generated by extension of rapid outpouring of Java. Continental flood in time to the early stages of the volcano's the lithosphere, 1. Petrol., 29, 625, 1988. basalt provinces are candidates for plume growth, and to produce from these samples Moore, J. G., Subsidence of the Hawaiian ridge, U.S. Ceo/. Surv. Prof Pap. 1350, 85, 1987. head-related volcanism [Richards et a/., an essentially continuous chemical and iso­ Moore, J. G., D. A. Clague, and W. R. Normark, 19891. The plume head is predicted to en­ topic record of the lava output. This time Diverse basalt types from Loihi seamount, Ha­ train large amounts of material external to series would provide a unique opportunity waii, Geology, 10, 88, 1982.

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Morgan, W. J., Convection plumes in the lower rameterized model for the evolution of isotopic -Y. Chen, and D. Clague, The isotope systemat­ mantle, Nature, 230, 42, 1971. heterogeneities in a convecting system, Earth ics of a juvenile intraplate volcano: Pb, Nd, and Okal, E. A., and R. Batiza, Hotspots: The first 25 Planet. Sci. Lett., 60, 178, 1982. Sr isotope ratios of basalts from Loihi seamount, years, in Seamounts, Islands, and Atolls, Geo­ Roden, M. F., F. A. Frey, and D. A. Clague, Hawaii, Earth Planet. Sci. Lett., 69, 13, 1984. phys. Monogr. Ser., vol. 43, edited by Keating et Geochemistry of tholeiitic and alkalic lavas from Stille, P., D. M. Unruh, and M. Tatsumoto, Pb, Sr, al., pp. I-ll, AGU, Washington, D.C., 1987. the Koolau Range, Oahu, Hawaii: Implications Nd, and Hf isotopic evidence of multiple Olson, P., and H. Singer, Creeping plumes, J. Fluid for Hawaiian volcanism, Earth Planet. Sci. Lett., sources for Oahu, Hawaii basalts, Nature, 304, Mech., 158,511, 1985. 69, 141, 1984. 25, 1983. Ribe, N. M., and M.D. Smooke, A stagnation point Schilling, J.- G., Icelandic mantle plume: Whitehead, J. A., and D. S. Luther, Dynamics of flow model for melt extraction from a mantle Geochemical evidence along the Reykjanes laboratory diapir and plume models, J. Geophys. plume, J. Geophys. Res., 92, 6437, 1987. Ridge, Nature, 242, 565, 1973. Res., 80, 705, 1975. Richards, M.A., R. A. Duncan, and V. E. Courtillot, Schilling, J. -G., and A. Noe-Nygaard, Faeroe-Ice­ Zindler, A., and S. R. Hart, Chemical geodynamics, Flood basalts and hot-spot tracks: Plume heads land plume: Rare Earth evidence, Earth Planet. Annu. Rev. Earth Planet. Sci., 14, 493, 1986. and tails, Science, 246, 103, 1989. Sci. Lett., 24, I, 1974. Zindler, A., E. Jagoutz, and S. Goldstein, Nd, Sr, Richter, F. M., Simple models for trace element Shaw, H. R., Mantle convection and volcanic perio­ and Pb isotopic systematics in a three-compo­ fractionation during melt segregation, Earth dicity in the Pacific: Evidence from Hawaii, Geol. nent mantle, Nature, 298, 519, 1982. Planet. Sci. Lett., 77, 333, 1986. Soc. Am. Bull., 84, 1505, 1973. Zindler, A., H. Staudigel, and R. Batiza, Isotope Richter, F. M., and D. P. McKenzie, On some con­ Spohn, T., and G. Schubert, Modes of mantle con­ and trace element geochemistry of young Pacific sequences and possible causes of layered man­ vection and removal of heat from the Earth's in­ seamounts: Implications for the scale of upper tle convection, J. Geophys. Res., 86, 6133, 1981. terior, J. Geophys. Res., 87, 4682, 1982. mantle heterogeneity, Earth Planet. Sci. Lett., 70, Richter, F. M., S. F. Daly, and H.- C. Nataf, A pa- Staudigel, H., A. Zindler, S. R. Hart, T. Leslie, C. 175, 1984.

been cut by $75 million, CRAF-Cassini by billion, came in for some hard knocks at the House Panel $45 million, and the Advanced X-Ray Astro­ hearing. (AGU also recently appeared before physics Facility by $50 million. With Free­ Congress to challenge NASA's estimate for dom removed, however, the original budget Freedom's cost; see Eos, May 7, 1991.) Both ''Terminates'' requests for EOS, CRAF, and AXAF survived Garn and Phil Gramm (R-Tex.) bluntly dis­ intact. The savings from deleting Freedom paraged GAO's credibility. GAO is "increas­ will also fund veterans' and environmental ingly unscientific," Gramm charged. Freedom programs and other social services. Truly defended NASA's cost estimate for PAGE 233 The subcommittee's "marked up" appro­ the space station, once again pleading that The House appropriations subcommittee priations bill, as its adjustments to the presi­ the station be taken off the "funding seasaw" with responsibility for the National Aeronau­ dent's budget request are called, is not the it has ridden the last few years. "Without the tics and Space Administration terminated final word on the space station. The bill funding that's requested, this country is not funding for Space Station Freedom on May must' now be approved by the full House going to see a space station," he said. 15. The surprise action by the VA, HUD, and appropriations committee. On the Senate The lone dissonant voice raised at the Independent Agencies subcommittee, side, the appropriations subcommittee hearing belonged to J. Robert Kerrey (D­ chaired by Bob Traxler (D-Mich.), threatens chaired by Barbara Mikulski (D-Md.) has not Nebr.), who expressed concern about Free­ a favorite space project of the Bush adminis­ yet made its own recommendations on a dom's scientific usefulness. "I support the tration, and calls into question the generally narallel bill.--l..ynn Teo Simarski space station but it's a very tentative sup­ strong support for the space station believed port," he said. to exist in Congress. When Kerrey brought up NASA's science Traxler cited budget constraints to justify Senate Handles NASA programs, Truly called them "the jewel in the act. The funding cut-off, he said, "reflects NASA's crown." When Kerrey asked whether the fact that our federal government's bud­ Gently-So Far or not NASA's space science progr~ms were geting has hit a dead end. We simply can no PAGE 233 being "robbed" to fund other projects, Truly longer afford huge new projects, with huge "When we ask these tough questions to­ answered that this wa$ "definitely a misper­ pricetags, while trying to maintain services day, know that they're so we can really argue ception." AGU and other scientific societies that the American public expect to be pro­ the case of NASA," Senator Barbara Mikulski continue to remind C0;11gress about the Au­ vided." (D-Md.) told Richard Truly, administrator of gustine Committee's recommendation that In terminating Freedom, Traxler added, the National Aeronautics and Space Adminis­ science be NASA's first priority. Truly the subcommittee was "able to provide tration, on May 8 as she opened a succinct seemed to be responding to this when he nearly full funding for other space science and generally friendly hearing on NASA's said, "I believe that one of the worst mis­ research efforts, and we have provided full budget. The gentle tone of Mikulski and takes that could be made with regard to the funding for the research and education pro­ most of the subcommittee on VA, HUD, and Augustine report is for each part of the grams of the National Science Foundation." Independent Agencies that she chairs was in space constituency to reach into the report Other sources, however, indicate that the striking contrast to the contentious reception and pull out their favorite sentence, their subcommittee deleted the funding for the Truly and Space Station Freedom got the pre­ favorite program, and put that above all." At NSF's Laser Interferometer Gravitational Ob­ vious week from a House committee. one point, Gramm said that the real issue servatory (LIGO), freeing up money to in­ Evidently prepared for another possible regarding NASA is not science but "Ameri­ crease other NSF programs beyond the ad­ confrontation, the NASA head brought along ca's leadership in space." ministration's request. enough of his top staff to fill the first two The House and Senate budget resolution "'This is a very serious blow"' to the rows of the hearing room, but he faced just passed on the floor of Congress sug­ space station, Robert S. Walker (R-Pa.) was mostly supportive senators. Mikulski pledged gested cutting NASA's budget by $1.2 billion. quoted as saying in the May 16 Washington to be "a very strong advocate for the NASA Mikulski asked whether the space station Post. "Walker said it would be 'very hard' to core." Ranking minority member Jake Garn would still be worth funding if this cut were reverse the decision and would 'take major (R-Utah) was also positive about NASA, actually made. Truly implied that in such a pressure from the [Bush) administration."' while calling upon President Bush to lobby case all NASA sectors would suffer, saying The subcommittee released figures that personally for his generous NASA request. that "a cut that deep would put not just the compared its cuts to NASA's budget request "The most serious issue NASA faces in space station for a 're-look' but also the with and without Freedom. By retaining the this climate of tight budget is the future of space science programs" and others. space station, the subcommittee would have the space station," Mikulski said. The Gen­ Rumors persist in Washington, however, made a "general reduction" of $35 million in eral Accounting Office's recent study of Free­ that a large portion of the cut will affect ei­ NASA's space science and applications area. dom, which charged NASA with underesti­ ther NASA's science programs or the space Also, the Earth Observing System would have mating the station's cost up to 1999 by $10 station, but not both.

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