- Email: [email protected]
Geophysics of the polar regions
Physics of the Earth and Planetary Interiors, 44 (1986) 377—378 Elsevier Science Publishers By., Amsterdani — Printed in The Netherlands
377
Book reviews Geophysics of the Polar Regions. E.S. Husebye, G.L. Johnson and Y. Kristoffersen (Editors), Elsevier, Amsterdam, 1985, 470 PP., US $98.25, 1 Dfl. 265.00. Geophysics of the Polar Regions comprises selected papers from a symposium on that theme held during the 1983 I.U.G.G. 18th General Assembly in Hamburg. The three editors are, through their own field experience, experts on geology and geophysics of marine and continental polar regions of both hemispheres. They have collected a number of very exciting papers in this volume which allow us to compare aspects of geology and geophysics of both the northern and the southern polar regions. In general, the contributions of this book are grouped around four major topics, namely (1) geology and geophysics of the Arctic Basin and adjacent seas, (2) geology and crustal structures of Svalbard and Barents Sea, (3) geophysics of the southern oceans, and (4) geology and resources of the Antarctic continental margin. Altogether, they represent a timely collection of data and new insight into the geological properties and history of some of the remotest, and therefore least known, areas of our world which are now receiving a lot of attention. However, from the excitement generated by these papers, it appears that those addressing the properties of the polar oceans are winning over those discussing the areas underlain by continental crust. Although the title of the first paper of the book sounds a bit trivial, this paper contains Sweeney’s very interesting idea that the Canada Basin only opened during Cretaceous time. It is followed by Jackson’s interesting interpretation of the origin and nature of a suture zone underlying the Nares Strait; it remains to be seen if her idea of the
Phanerozoic opening and closing of an ocean basin leading to the formation of Nares Strait will stand future scrutiny. Snvastava then discusses plate kinematic solutions of late Mesozoic and Cenozoic movements along the Nares Strait, and Duckworth and Baggeroer present an extensive account and interpretation of seismic refraction data from the Fram and Nansen basins of the Arctic Ocean. It is followed by Kristoffersen and Husebye’s description of the FRAM-IV multichannel seismic reflection lines which offers an interesting new insight into sediment stratification in the deep-sea basin north of Yermak Plateau. After ODP Leg 104 drilling resolved composition of the dipping reflector sequence of the Vonng Plateau in mid1985, it is known that Mutter’s (and others) assumption of their volcanic origin was correct, a!though prior to the availability of the drilling results he had been unable to define the exact nature of the assumed volcanic rocks of the dipping reflector sequence itself. Dinter’s important contribution to the understanding of the offshore stratigraphy of the Quaternary Gubik Formation in Arctic Alaska provides deep insight into the depositional processes on an Arctic shelf adjacent to a formerly repeatedly glaciated area; the tentative correlations of his seismic stratigraphy to the Quaternary chonostratigraphy point to the importance of future detailed dating of the offshore Gubik Formation. Geophysical properties of the southern oceans have been addressed in three papers. Lawyer, Sciater and Meincke provide insight into the plate tectonic history of the breakup of Gondwana with a detailed account of the area of Drake Passage and Scotia Sea, including the overlaps of the Antarctic Peninsula with the region of continental crust surrounding the Falkland Islands. Mutter and co-authors have developed a model of sea floor spreading between Australia and Antarctica which invokes an early breakup at 85 Ma and a
378
time span of very slow spreading between magnetic anomalies 34 and 19. The contributions to Svalbard and the Barents Sea comprise a wide set of different topics, such as the reconstruction of Mesozoic and Palaeozoic palaeomagnetic poles for Svalbard, intraplate earthquakes on Svalbard, the tectonic evolution of the West Spitsbergen Fold Belt, and the crustal structure of the Barents Sea shelf. The papers on the Antarctic continental margin geology are equally diverse. The nature and crustal structure of the Weddell Sea embayment, of the Prydz Bay region, of McMurdo Sound, and of Bransfield Strait has been described in a number of studies largely based on seismic reflection data. Earthquake swarms at Mt. Erebus, data on crustal structure of the Ongul Islands and Mizuko Plateau (East Antarctica), a paper on the volcanic and tectonic late Cenozoic to Recent evolution of the northern Antarctic Peninsula and an account of the possible hydrocarbon potential of the Antarctic margin complete this volume, Geophysics of the Polar Regions is the typical result of one of the many scientific gatherings of people interested in a specific subject; and it probably includes many of the relevant players of the early Eighties. It is still conspicuous that scientists from some countries, known to be active in the polar regions, are lacking or are scarcely represented in this book. The editors are well familiar with their subject guaranteeing scientific soundness of the individual contributions. With the data base from both polar regions at hand it is now possible to compare geophysical properties and geologic evolution with some exciting prospects for future studies. J. THIEDE (Kiel, F.R.G.)
The Mystery of Comets. F.L. Whipple, Cambridge University Press, Cambridge, 1986, 200 pp., £12.95, ISBN 0 521 324408. It is common practice at many social gatherings to serve the good wine first and then progress to the cheaper variety. After the flood of books on Halley’s comet that have recently appeared, I was glad to see that the publishing world have reversed this trend, keeping the best till near the end. I was attracted to this book from the very first sentence which echoed my own thoughts, namely why should people be so afraid of an object as slow moving and graceful as a comet. The book answers this question and provides an entertaining and informative account of the history of cometary, and to some extent, planetary science. The book is, however, much more than a history text book, it also contains an authoritative account of our present state of knowledge regarding comets. Though Fred Whipple is regarded by most people as the outstanding cometary expert of our time, the book is very generous in the amount of space it devotes to other astronomers, in particular those that did not see eye to eye with Whipple on the fundamental point of the nature of comets. It is perhaps a tribute to the insight of Whipple that the science described in the book does not really need any modifying as a consequence of the Halley armada of spacecraft, the cometary nucleus, consisting of about 80% water—ice was there, just as predicted. In sharp contrast to many other space efforts, we had got the science right and there were no major surprises waiting for us. Any attempt on my part to summarise the content of the book will inevitably lead to a loss of flavour and it is sufficient to say that the book is a must for everyone who is interested in cometary science. To us in the Northern Hemisphere, reading the book will prove far more rewarding than attempting to observe Halley on a cold November night. I.P. WILLIAMS (London, Gt. Britain)
377
Book reviews Geophysics of the Polar Regions. E.S. Husebye, G.L. Johnson and Y. Kristoffersen (Editors), Elsevier, Amsterdam, 1985, 470 PP., US $98.25, 1 Dfl. 265.00. Geophysics of the Polar Regions comprises selected papers from a symposium on that theme held during the 1983 I.U.G.G. 18th General Assembly in Hamburg. The three editors are, through their own field experience, experts on geology and geophysics of marine and continental polar regions of both hemispheres. They have collected a number of very exciting papers in this volume which allow us to compare aspects of geology and geophysics of both the northern and the southern polar regions. In general, the contributions of this book are grouped around four major topics, namely (1) geology and geophysics of the Arctic Basin and adjacent seas, (2) geology and crustal structures of Svalbard and Barents Sea, (3) geophysics of the southern oceans, and (4) geology and resources of the Antarctic continental margin. Altogether, they represent a timely collection of data and new insight into the geological properties and history of some of the remotest, and therefore least known, areas of our world which are now receiving a lot of attention. However, from the excitement generated by these papers, it appears that those addressing the properties of the polar oceans are winning over those discussing the areas underlain by continental crust. Although the title of the first paper of the book sounds a bit trivial, this paper contains Sweeney’s very interesting idea that the Canada Basin only opened during Cretaceous time. It is followed by Jackson’s interesting interpretation of the origin and nature of a suture zone underlying the Nares Strait; it remains to be seen if her idea of the
Phanerozoic opening and closing of an ocean basin leading to the formation of Nares Strait will stand future scrutiny. Snvastava then discusses plate kinematic solutions of late Mesozoic and Cenozoic movements along the Nares Strait, and Duckworth and Baggeroer present an extensive account and interpretation of seismic refraction data from the Fram and Nansen basins of the Arctic Ocean. It is followed by Kristoffersen and Husebye’s description of the FRAM-IV multichannel seismic reflection lines which offers an interesting new insight into sediment stratification in the deep-sea basin north of Yermak Plateau. After ODP Leg 104 drilling resolved composition of the dipping reflector sequence of the Vonng Plateau in mid1985, it is known that Mutter’s (and others) assumption of their volcanic origin was correct, a!though prior to the availability of the drilling results he had been unable to define the exact nature of the assumed volcanic rocks of the dipping reflector sequence itself. Dinter’s important contribution to the understanding of the offshore stratigraphy of the Quaternary Gubik Formation in Arctic Alaska provides deep insight into the depositional processes on an Arctic shelf adjacent to a formerly repeatedly glaciated area; the tentative correlations of his seismic stratigraphy to the Quaternary chonostratigraphy point to the importance of future detailed dating of the offshore Gubik Formation. Geophysical properties of the southern oceans have been addressed in three papers. Lawyer, Sciater and Meincke provide insight into the plate tectonic history of the breakup of Gondwana with a detailed account of the area of Drake Passage and Scotia Sea, including the overlaps of the Antarctic Peninsula with the region of continental crust surrounding the Falkland Islands. Mutter and co-authors have developed a model of sea floor spreading between Australia and Antarctica which invokes an early breakup at 85 Ma and a
378
time span of very slow spreading between magnetic anomalies 34 and 19. The contributions to Svalbard and the Barents Sea comprise a wide set of different topics, such as the reconstruction of Mesozoic and Palaeozoic palaeomagnetic poles for Svalbard, intraplate earthquakes on Svalbard, the tectonic evolution of the West Spitsbergen Fold Belt, and the crustal structure of the Barents Sea shelf. The papers on the Antarctic continental margin geology are equally diverse. The nature and crustal structure of the Weddell Sea embayment, of the Prydz Bay region, of McMurdo Sound, and of Bransfield Strait has been described in a number of studies largely based on seismic reflection data. Earthquake swarms at Mt. Erebus, data on crustal structure of the Ongul Islands and Mizuko Plateau (East Antarctica), a paper on the volcanic and tectonic late Cenozoic to Recent evolution of the northern Antarctic Peninsula and an account of the possible hydrocarbon potential of the Antarctic margin complete this volume, Geophysics of the Polar Regions is the typical result of one of the many scientific gatherings of people interested in a specific subject; and it probably includes many of the relevant players of the early Eighties. It is still conspicuous that scientists from some countries, known to be active in the polar regions, are lacking or are scarcely represented in this book. The editors are well familiar with their subject guaranteeing scientific soundness of the individual contributions. With the data base from both polar regions at hand it is now possible to compare geophysical properties and geologic evolution with some exciting prospects for future studies. J. THIEDE (Kiel, F.R.G.)
The Mystery of Comets. F.L. Whipple, Cambridge University Press, Cambridge, 1986, 200 pp., £12.95, ISBN 0 521 324408. It is common practice at many social gatherings to serve the good wine first and then progress to the cheaper variety. After the flood of books on Halley’s comet that have recently appeared, I was glad to see that the publishing world have reversed this trend, keeping the best till near the end. I was attracted to this book from the very first sentence which echoed my own thoughts, namely why should people be so afraid of an object as slow moving and graceful as a comet. The book answers this question and provides an entertaining and informative account of the history of cometary, and to some extent, planetary science. The book is, however, much more than a history text book, it also contains an authoritative account of our present state of knowledge regarding comets. Though Fred Whipple is regarded by most people as the outstanding cometary expert of our time, the book is very generous in the amount of space it devotes to other astronomers, in particular those that did not see eye to eye with Whipple on the fundamental point of the nature of comets. It is perhaps a tribute to the insight of Whipple that the science described in the book does not really need any modifying as a consequence of the Halley armada of spacecraft, the cometary nucleus, consisting of about 80% water—ice was there, just as predicted. In sharp contrast to many other space efforts, we had got the science right and there were no major surprises waiting for us. Any attempt on my part to summarise the content of the book will inevitably lead to a loss of flavour and it is sufficient to say that the book is a must for everyone who is interested in cometary science. To us in the Northern Hemisphere, reading the book will prove far more rewarding than attempting to observe Halley on a cold November night. I.P. WILLIAMS (London, Gt. Britain)