摘要:

Recent advances in lunar sample science and planetary accretion theories demand a new look at the bombardment history recorded by the Moon. Among lunar samples there are no impact melts dated older than about 3.9 Ga, yet a heavy bombardment of the Moon from its birth until 3.9 Ga should have produced many melts to be sampled by Apollo, Luna, and the meteorites of lunar origin. The absence of older impact melts cannot be explained by continued isotopic resetting because ejecta blankets are mainly cold and ancient igneous rocks including mare basalts exist. The common 3.85‐Ga melt ages cannot be ascribed to a single or even a few basin events (e.g., Imbrium) because the samples show wide differences in chemistry and real, if small, differences in ages; the ages also appear in the lunar meteorites and thus are Moon‐w

ISSN:0002-8606    

DOI:10.1029/90EO00086

年代:1990

数据来源: WILEY

摘要:

The U.S. WOCE Hydrographic Program Implementation Panel (WHPIP) and the U.S. WOCE Science Steering Committee (SSC) on January 26 established the procedure for selecting ancillary projects on U.S. WOCE Hydrographic Program (WHP) cruises.WOCE is the World Ocean Circulation Experiment, an international effort to understand how the ocean circulation affects climate, to help make it possible to predict climate changes over periods of decades and to discover how human activity is influencing climate patterns (“The WOCE Hydrographic Project,”Eos, 69, 68, 1988, and “U.S. WOCE Program Ready to Begin,”Eos, 70, 874

ISSN:0002-8606    

DOI:10.1029/EO071i010p00314-02

年代:1990

数据来源: WILEY

摘要:

The President's budget request for the National Aeronautics and Space Administration contains a dramatic increase of 24%, or $2.8 billion, over Fiscal Year 1990, bringing the total figure for FY 1991 to $15.1 billion. Of the $4.5 billion the administration has proposed in increases for civilian and defense R&D, NASA receives $2 billion. The largest single increase in the NASA budget is slated for Space Station Freedom, which increases by $700 million (36%) to a total of $2.6 billion. Other big increases go to the lunar/Mars initiative, which is up 47% to a total of $408 million, and the first element of NASA's Mission to Planet Earth, the Earth Observing System (EOS), to receive $264 million.

ISSN:0002-8606    

DOI:10.1029/EO071i010p00315-01

年代:1990

数据来源: WILEY

摘要:

Two themes emerged from the Clay Mineral Society's 1989 meeting: We need to consider larger samples, whether in theoretical or experimental work—count more spacings in HRTEM photos, and take multiple samples from single locations; and the configurations R0, Rl, (R2) and R3 have some kind of distinct stability. Kaolinite also got its share of attention, even though no session was devoted to it.The society met September 23–28, 1989, at California State University, Sacramento; 195 scientists attended. Although there were fewer presentations than in recent years, participants agreed that quality was improved and that more time allowed for more and better discussi

ISSN:0002-8606    

DOI:10.1029/90EO00094

年代:1990

数据来源: WILEY

摘要:

Active volcanos and their associated earthquakes are by far the most dramatic elements of Hawaii's natural history heritage. Indeed, the islands owe their very existence to these forces of nature, so it is not surprising that a host of scientists, journalists, and an even wider variety of citizen observers have, over the years, created a rich and diverse written record of their findings. This volume is the result of an exhaustive effort to gather and distill information from all available references on volcanism and seismicity for the period 1779–1955, a task of enormous proportion

ISSN:0002-8606    

DOI:10.1029/EO071i010p00324

年代:1990

数据来源: WILEY

摘要:

Lake Baikal in the U.S.S.R. and Lake Superior in the U.S. will be paired for studying global freshwater problems, by terms of an agreement signed in January by U.S. and Soviet ecological organizations. They will establish twin facilities to be internationally managed at the two lakes, exchange scientists and information, and translate and publish information on global freshwater issues.The Lake Superior Center, Duluth, Minn., signed protocols with four Soviet ecological organizations and added four Soviet citizens to its board of directors. The center also has arranged for 10 Soviet scientists to attend an international freshwater conference in fall 1990 in Duluth. The conference will address scientific issues relating to large lakes.

ISSN:0002-8606    

DOI:10.1029/EO071i010p00325-01

年代:1990

数据来源: WILEY