摘要:

On December 25, 1989, a magnitude Ms 6.3 earthquake in the Ungava peninsula of Northern Quebec, Canada, produced the first surface rupture in Eastern North America [Adams et al., 1991]. An integrated analysis of remotely sensed data and total field aeromagnetic was done to improve our understanding of the earthquake's regional geological environment. Lineament information extracted from remotely sensed and magnetic data can provide additional geological constraints to seismic hazard assessment.Much emphasis has been placed on Synthetic Aperture Radar (SAR) data in the promotion of remotely sensed data within the Geological Survey of Canada. Nationally and internationally, SAR data has been proven to be an effective tool for Earth sensing. As a result, many countries are developing spaceborne radar systems: Canada (RADARSAT), the United States (SIR‐C), Europe (ERS‐1), and Japan (JERS‐1). Active radar imaging using longer electromagnetic wavelengths penetrates cloud cover independent of Sun illumination. This effectively allows all‐weather data collection. SAR side‐viewing geometry offers a unique pseudo‐three‐dimensional view of the terrain surface, enhancing terrain geometry and surf

ISSN:0002-8606    

DOI:10.1029/93EO00487

年代:1993

数据来源: WILEY

摘要:

On April 1–2, talk at University College London focused on failure and the stresses and strains that cause it. The discussion was aimed at improving our understanding of crack systems in rocks, their effect on the physical properties of the bulk rock, and their response to applied stresses and strains up to rock failure.“Crack Systems in Rocks: Fundamentalsand Application to Crustal Dynamics and Reservoir Engineering,” a meeting organized by Philip Meredith, Paul Glover, and Peter Sammonds, was initially designed as a gathering of scientists collaborating with the Rock and Ice Physics Laboratory at University College London. However, interest in the meeting grew to an international scope, with participants coming from as far away as Japan, the United States, Sweden, and

ISSN:0002-8606    

DOI:10.1029/93EO00426

年代:1993

数据来源: WILEY

摘要:

Peter H. Feldhausen, 58, died on May 26. He joined AGU (Hydrology) in 1958.Butler King Couperdied on June 18 at age 87. He had been a member of AGU (Ocean Sciences) since 1948.

ISSN:0002-8606    

DOI:10.1029/EO074i032p00355-01

年代:1993

数据来源: WILEY

摘要:

In recognition of his many contributions to geodesy, the United Kingdom's Military Survey's new headquarters building was named after Brigadier Guy Bomford at a ceremony at Feltham near London on July 10, 1992. He was the director of survey of the southeast Asia command during World War II, was reader in geodesy at Oxford University, was active in the International Union of Geodesy and Geophysics (serving as president from 1963 to 1967), and is the author of the well‐known text,Geodesy.Now aged 92, Bomford unveiled a plaqueon the building and attended a luncheon at the Feltham Officer's Mess hosted by the Director General of Military Survey, Major General Roy Woo

ISSN:0002-8606    

DOI:10.1029/93EO00292

年代:1993

数据来源: WILEY

摘要:

Guyots are flat‐topped seamounts that are most common on Mesozoic‐age Pacific oceanic crust. Dredging of the Pacific guyots, of which over 300 are known, commonly revealed the existence of mid‐Cretaceous rudist reefs and other shallow‐water carbonate facies, now submerged to depths on the order of 1000‐1500 m, capping volcanic edifices [Lincoln et al., 1993].The intriguing question of how guyots originate played a major role in the development of concepts of seafloor spreading, hot spots, thermal subsidence and crustal thinning, and superswells [e.g.,Hess, 1962;Detrick and Crough, 1978;Menard, 1964, 1984]. However, key questions remain, such as why a tropical carbonate platform would suddenly cease to keep pace with subsidence after constructing a massive carbonate cap up to 1000‐m thick and tens of kilometers in diameter, or why the apparent ages of the underlying volcano and of the shallow‐water carbonate cap as determined from dredge samples appeared to lack the coherent patterns predicted from hot‐spot and subs

ISSN:0002-8606    

DOI:10.1029/93EO00458

年代:1993

数据来源: WILEY