Vulkanologi og seismologi

Beslutningen om at realisere en gennemfotografering af Grønland fra luften var oprindeligt motiveret af et ønske om over for omverdenen at sikre Danmarks position som suverænitetsbærende nation i Arktis. Den enorme samling af luftfotografier, der blev resultatet af disse bestræbelser, udgjorde en hjørnesten i den teknologiske transformation, som i mellemkrigstiden revolutionerede kortlægningsarbejdet, sikrede Grønland for Danmark og gav os et unikt grundlag for i dag at studere effekten af klimaændringer på Grønlands indlandsis gennem de seneste 80 år.

Inge Lehmann, 1888-1993, var geofysiker og var med til at grundlægge seismologien, en helt ny videnskab, i 1930’erne og årtierne derefter. En lidenskabelig trang til at blive til noget, havde fået hende til at overhøre alle de velmente råd fra sin familie, der på ingen måde syntes, hun skulle studere, og hun endte med at blive den første kvindelige seismolog i verden. I 1936 fremførte hun hypotesen, at Jorden har en fast indre kerne, hvilket skulle vise sig at være rigtigt. Hun trådte ind i en international forskerverden med imødekommende kollegaer, men hjemme i Danmark mødte hun akademisk snobberi, mandschauvinisme og vanetænkning.Skyggezone, af biolog og forfatter Hanne Strager, er den første biografi skrevet om Inge Lehmann. Bogen er blevet til på baggrund af en lang række breve, dokumenter og videnskabelige artikler fra Rigsarkivet og personlige breve i familiens eje, som alt sammen er med til at tegne et nyt og nuanceret billede af vores store danske seismolog.

”Skrub ad hekkenfeldt til!”I gamle dage betød det gå ad helvede til. Og den islandske vulkan Hekla – hekkenfeldt – var nedgangen til infernoets evige pinsler.Efter det voldsomme udbrud i 1104 florererede ideen i Europa om, at Gud lod indgangen stå åben til skræk og advarsel for syndige mennesker. Myten varede indtil det 19. århundrede, hvor bjergbestigere forsigtigt begyndte at udfordre bjerget. Forsigtigt, fordi de var skrækslagne – Hekla er relativt nem at bestige, men alligevel tog det fem årtier, før nogen turde vove sig til tops.Hekla er også det sted, hvor alverdens hekse ifølge overleveringerne mødes med selveste Djævelen på sankthansaften og valborgsaften. Legenderne, myterne og alle de andre skrøner drejer sig i virkeligheden om en yderst fascinerende vulkan, og med Hekla – Islands dronning har Henning Andersen skrevet en kærlighedserklæring til bjerget med den brogede historie. Uddrag af bogen I Miraklernes bog, skrevet af den hellige klosterreformator og munk Herbert fra Clairvaux, finder vi en af de ældste beskrivelser om Islands Helvede fra 1100-tallet:”Det vides, at der i Norden findes en ø, kaldet Island, som er underlagt den kristne tro. Men på den findes der et stejlt og umådeligt bjerg, der dækker en stor del af egnen, og de lokale indbyggere mener, at der neden under dette bjerg og inden i det findes et kæmpemæssigt helvede. For dette bjerg, som på alle sider er fuld af huller og hulheder, gløder over det hele, spyr flammer og udsender en evig ild, der gennemtrænger og ødelægger det udvendigt og indvendigt helt ned til dets fod, ja endog hinsides foden af bjerget. Thi det bekræftes af sikre beviser, at denne rædselsvækkende ild lever og raser ikke alene nede under bjergets grundvold, men under havets bund.” Om forfatteren Henning Andersen begyndte allerede i 1960’erne som rejseleder for at få lejlighed til at studere vulkaner verden over. Dette er han fortsat med til i dag, både som guide og privat, og han udtaler sig ofte som ekspert inden for emnet i radio og tv. Hans hjemmeside hedder: www.vulkaneksperten.dk.Hennings vulkaninteresse fik stærk fornyet kraft, da han vandt i Otto Leisners “Kvit eller Dobbelt” i 1985. Han er en garvet foredragsholder der gang på gang har tryllebundet publikum med sin store viden. Hennings mission er at beskrive og forklare “Moder Jords” mystiske og utæmmelige kræfter på en levende måde. Vulkanen Hekla er Hennings yndlingsvulkan.

Når man nævner ordet vulkan, fremkalder man som regel Vesuvs smukke bjerg for det indre øje. For det første så lægger Vesuv navn til en af de kendteste vulkankatastrofer i verden, hvor den romerske by Pompeji blev begravet i pimpsten og aske i året 79. e.Kr. Efter genopdagelsen og udgravningen af Pompeji i 1748 startede, førte det til, at alverdens arkæologer rejste til ruinbyerne ved Vesuv, men også selve udforskningen af vulkanen tog til, da Vesuv i de år befandt sig i en virksom udbrudsrytme. For det andet finder vi her den første og realistisk forklarende beskrivelse af et vulkanudbrud på Jorden i Plinius den Yngres to breve til den romerske historiker Tacitus. Disse breve er en vulkanologisk korrekt fortolkning af et eksplosivt vulkanudbrud, så vulkanologer i dag kalder denne type vulkanudbrud for ”plineansk vulkanaktivitet”. For det tredje grundlagde den napolitanske konge i 1841-45 et vulkanobservatorium på Vesuvs nordlige skråning, det første af sin art i verden, og herfra er vulkanens udbrud blevet studeret intenst, og meget af det, som vi i dag ved om vulkaner, stammer fra forskning på Vesuv. Endelig så ligger Vesuv i verdens tættest befolkede område med i dag snart 4 millioner mennesker inden for rækkevidden af en eksplosiv vulkan foruden de to andre nærliggende vulkaner såsom Campi Flegrei og vulkanen på øen Ischia, der er lige så truende. Disse vulkaner er omtalt i bogen, da de er lige så stor en trussel for indbyggerne som Vesuv. Uddrag af bogen Historien om Vesuv og Pompeji hænger sammen. Fra det 17. århundrede rejste kunstnere og forfattere til de udgravede byer ved Vesuv, men også for at beundre selve vulkanen. Fra Danmark kom Bertel Thorvaldsen, Constantin Hansen, Chr. den 8. og H.C. Andersen. Chr. den 8. skrev om en lavastrøms størkning på vulkanens flanke og om, hvordan der udskilles krystaller ved selve størkningen. Denne mineralogiske afhandling var på tysk, og jeg har oversat den til dansk som et kapitel i denne bog. Vesuv befandt sig i disse år i en meget aktiv udbrudsrytme med en konstant røgsøjle hele tiden, hvilket stadig kan ses på gamle postkort. H.C. Andersens beskrivelse af Vesuv set fra havnemolen i Napoli og hans egen bestigning af Vesuv er meget levende beskrevet, og jeg har tilføjet hans beretning og hans digt om Vesuv efter tilladelse og gengivelse fra H.C. Andersens Museum i Odense, da jeg skulle indspille en film om de italienske vulkaner. I min bog Mod Vesuv jeg øjet vender, der handler om H.C. Andersens fascination af vulkanen Vesuv, er denne beskrivelse og digtet også gengivet, og jeg fik Jesper Klein til at læse dem op i filmen.Om forfatteren Vulkaneksperten Henning Andersen, har viet sit liv til vulkanerne, har skrevet en del bøger om emnet og er i dag foredragsholder og underviser i folkeskolerne. Han blev i sin tid kendt hos Otto Leisner som vinder i ”Kvit eller Dobbelt”, hvorefter han læste geologi og har som rejseleder og privat besøgt vulkaner rundtom i verden. Han har tidligere udgivet bøgerne Hekla – Islands dronning, Når vulkaner går amok, Sagn og myter om vulkaner og nu Vesuv – en udødelig vulkan, der er hans fjerde bog om Vesuv, som også er Hennings yndlingsvulkan. Hans hjemmeside om vulkaner hedder: www.vulkaneksperten.dk.

Every-day adventurer, Mark Barsdell, is training and working as a geologist in the 1970's when he comes upon opportunities to explore the far reaches of our planet. Through expeditions, field trips and personal adventures, he traverses the most remote regions of Antarctica, the New Hebrides (Vanuatu) and the Arctic, as well as volcanic regions of New Zealand, North America, Mexico and Argentina. Keeping meticulous records of the environments in which he was immersed, his diaries offer a fascinating insight into regions less travelled. Have you ever wondered what it would be like to live on an ice-island, become lost for days on an active volcano, share a tent with an elephant seal or play hopscotch over a pool of hot sulfuric acid? Mark's travels were at a time when true adventure was possible, and through his diaries we can follow his intrepid footsteps.

First published in 2023 in the United Kingdom by Hodder & Stoughton.

'A fantastic account of the power and importance of volcanoes to history ... A book that will make all readers want to become volcanologists.'PETER FRANKOPAN'Beautiful. Mountains of Fire is bursting with poetry, with storytelling. ' WERNER HERZOGVolcanoes mean so much more than threat and calamity. Like our parents, they've led whole lives before we get to know them. We are made of the same stuff as the breath and cinders of volcanoes. They have long shaped the path of humanity, provoked pioneering explorations and fired up our imaginations. They are fertile ground for agriculture, art and spirituality, as well as scientific advances, and they act as time capsules, capturing the footprints of those who came before us.World-renowned volcanologist Clive Oppenheimer has worked at the crater's edge in the wildest places on Earth, from remote peaks in the Sahara to mystical mountains in North Korea. His work reveals just how entangled volcanic activity is with our climate, economy, politics, culture and beliefs. From Antarctica to Italy, he paints volcanoes as otherworldly, magical places where our history is laid bare and where nature speaks to something deep within us.Blending cultural history, science, myth and adventure, Mountains of Fire reminds us that, wherever we are on the planet, our stories are profoundly intertwined with volcanoes.

"You have heard of Pangea, the single landmass that broke apart some 175 million years ago to give us our current continents. What about its previous iterations, Rodinia or Columbia? These "supercontinents" from Earth's past provide evidence that continents repeatedly join and divorce. Scientists debate exactly what that next supercontinent will look like (and what to name it), but they agree that one is coming. In this book, Ross Mitchell, a geophysicist who researches the supercontinent cycle, offers a tour of past supercontinents; introduces readers to the phenomena that will lead to the next one; and presents the case for a particular future supercontinent, called Amasia, that will form over the North Pole. Mitchell uses compelling stories of fieldwork and accessible descriptions of current science to introduce readers to the nuances of plate tectonic theory. He considers convection deep in Earth's mantle to explain the future formation Amasia (defined by the joining of North America and Asia) and to show how this developing theory can explain other planetary mysteries. He ends the book by asking if humans will live to see Amasia. He recognizes the chances of our species surviving the necessary 50 to 200 million years are vanishingly small, but the exercise gives readers a chance to imagine this landscape and to understand mimics for the geological processes required, for example in the form of geoengineering. An internationally recognized authority on the supercontinent cycle, Mitchell offers a compelling and updated introduction that offers readers a front-row seat to an ongoing scientific debate"--]cProvided by publisher.

A tour of the Solar System's tallest, hottest, coldest and weirdest volcanoes - and a look inside what makes them erupt.The volcano - among the most familiar and perhaps the most terrifying of all geological phenomena. However, Earth isn't the only planet to harbour volcanoes. In fact, the Solar System, and probably the entire Universe, is littered with them. Our own Moon, which is now a dormant piece of rock, had lava flowing across its surface billions of years ago, while Mars can be credited with the largest volcano in the Solar System, Olympus Mons, which stands 25km high. While Mars's volcanoes are long dead, volcanic activity continues in almost every other corner of the Solar System, in the most unexpected of locations. We tend to think of Earth volcanoes as erupting hot, molten lava and emitting huge, billowing clouds of incandescent ash. However, it isn't necessarily the same across the rest of the Solar System. For a start, some volcanoes aren't even particularly hot. Those on Pluto, for example, erupt an icy slush of substances such as water, methane, nitrogen or ammonia, that freeze to form ice mountains as hard as rock. While others, like the volcanoes on one of Jupiter's moons, Io, erupt the hottest lavas in the Solar System onto a surface covered in a frosty coating of sulphur.Whether they are formed of fire or ice, volcanoes are of huge importance for scientists trying to picture the inner workings of a planet or moon. Volcanoes dredge up materials from the otherwise inaccessible depths and helpfully deliver them to the surface. The way in which they erupt, and the products they generate, can even help scientists ponder bigger questions on the possibility of life elsewhere in the Solar System.Fire and Ice is an exploration of the Solar System's volcanoes, from the highest peaks of Mars to the intensely inhospitable surface of Venus and the red-hot summits of Io, to the coldest, seemingly dormant icy carapaces of Enceladus and Europa, an unusual look at how these cosmic features are made, and whether such active planetary systems might host life.

Originally published in 1995, Monitoring Active Volcanoes is a comprehensive text which addresses the importance of volcano surveillance in the context of forecasting eruptive activity and mitigating its effects.

A San Francisco Chronicle BestsellerRead the rocks as only a geologist can, with this deep drill-down into Oakland’s geological history and its impacts on the city’s urban present."This book has turned me into a newcomer to my own city, but has also changed the way I will view any landscape. I can think of few greater gifts than that."—Jenny Odell, author of How to Do Nothing"Spending time with Andrew Alden is like giving yourself x-ray eyes." —Roman Mars, host and creator of 99% InvisibleBeneath Oakland’s streets and underfoot of every scurrying creature atop them, rocks roil, shift, crash, and collide in an ever-churning seismological saga. Playing out since time immemorial, the deep geology of this city has chiseled and carved its landforms and the lives of everyone—from the Ohlone to the settlers to the transients and transplants—who has called this singular place home.In Deep Oakland, geologist Andrew Alden excavates the ancient story of Oakland’s geologic underbelly and reveals how its silt, soil, and subterranean sinews are intimately entwined with its human history—and future. Poised atop a world-famous fault line now slumbering, Alden charts how these quaking rocks gave rise to the hills and the flats; how ice-age sand dunes gave root to the city’s eponymous oak forests; how the Jurassic volcanoes of Leona Heights gave way to mining boom times; how Lake Merritt has swelled and disappeared a dozen times over the course of its million-year lifespan; and how each epochal shift has created the terrain cradling Oaklanders today. With Alden as our guide—and with illustrations by Laura Cunningham, author of A State of Change—we see that just as Oakland is a human crossroads, a convergence of cultures from the world over, so too is the bedrock below, carried here from parts still incompletely known.

Progress in Volcanology includes nine chapters in three sections. The first section is the ¿Introduction¿ while the other two sections speak on ¿Applied Volcanology¿ and ¿Volcanic Sedimentology, Geochemistry and Petrology.¿ The chapters address volcanology in several areas around the world, including Italy, Indonesia, Ethiopia, Argentina, India, and others.

The main objective of the book is to present in-depth analysis of the theory and real implementations of seismic waves as versatile probes that would be integrated with modern and future perspectives. The current and the future strategies to be discussed in the relevant areas of seismic waves will be another boon for the readers.

GNSS Seismogeodesy: Theory and Applications combines GNSS and seismology theory and applications to offer both disciplines the background information needed to combine forces. It explores the opportunities for integrating GNSS and seismometers, as well as applications for earthquake and tsunami early warning applications. The book allows seismologists to better understand how GNSS positions are computed and how they can be combined with seismic data and allows geodesists to better understand how to apply GNSS to monitoring of crustal motion.This book is a valuable reference for researchers and students studying the interdisciplinary connection between GNSS geodesy and strong-motion seismology. It will also be ideal for anyone working on new approaches for monitoring and predicting geologic hazards.

Er gåden om det forsvundne Atlantis løst? Nye geologiske og arkæologiske fund på den græske vulkanø Santorini bringer en tabt kultur for dagens lys igen - måske den kultur, Platon beskrev i sin Atlantis-myte.Geologen Walter Friedrich har i mere end 30 år udforsket Santorini, og Ilden i havet er hans beretning om, hvordan vulkaner har præget øens historie, geografi og geologi. Bogens centrale tema er skildringen af, hvordan Santorinis blomstrende bronzealderkultur blev begravet under et tykt lag aske ved et af de kraftigste udbrud nogenskinde.Santorini-vulkanen minder os om, at vi er de små og naturen den store: Vulkaner lever deres eget uforudsigelige liv og kan omstyrte menneskelige kulturer på få minutter.

When the Greek island of Santorini, classically known as Thera, erupted dramatically in 1613 BC (+/- 13 years), it produced one of the largest explosions ever witnessed, thereby possibly giving rise to the legend of Atlantis. This so-called 'Minoan' eruption triggered tsunamis that devastated coastal settlements in the region, and on Santorini it left behind a Bronze Age Pompeji, which is currently being excavated. Thriving Bronze Age settlements on the island - rich in colorful wall paintings and highly sophisticated pottery - were buried under thick layers of volcanic ash. The ejection of an immense volume of dust into the atmosphere also altered global climate for several years.The author, a well-known geologist, blends the thrill of scientific discovery with a popular presentation of the geology, archeology, history, peoples, and the environmental settings of the island group of Santorini. He not only gives a comprehensive overview of the volcanic island and its past, but also reports on the latest discoveries: The finding, for example, of the olive trees which had been buried alive by the Minoan eruption has made it possible now to give a direct and precise radiocarbon date for the volcanic catastrophe. Furthermore, he seeks to assign certain geological structures, such as faulted rocks, red lavas and harbor sites, as depicted on the Bronze Age frescos from Santorini, to still-existing details in the Santorini landscape of today.Excellent color photographs and illustrations along with easily understandable scientific and historic details will make this book highly appealing to a wide audience. It will also be useful as a supplementary text for introductory courses in earth and atmospheric science, geology, volcanology, and paleoclimatology, as well as ancient history and archeology.