Acknowledgments

Returning to Uppsala in the autumn of 1995, after having spent a year in the California sunshine, I found myself in the extraordinary situation of being able to pick and choose from the smorgasbord of geophysical topics available at the department. It did not take very long though, before Reynir had convinced me that whatever I wanted to pursue in geophysics was available from the SIL network and that Iceland harboured more geophysically interesting problems than the rest of the world put together. What more is there to say? I joined the party and was awarded with two advisors, Ragnar Slunga and Reynir Böðvarsson. Working with these two skilled and creative scientists, not to mention incurable optimists, has been an adventure. Reynir was of course right about the problems, I ran my head into quite a few of them, but with Ragnar's words of wisdom and Reynir's helping hand, I managed to pound my way through.

I spent a couple of months of my studies in Iceland, at the Icelandic Meteorological Office in Reykjavik and at Hitaveita Akureyrar in Akureyri. Coming to work at the Met Office was always very productive and working with Sigurður Rögnvalsson was fun and educating. He was my big brother in SIL, teaching me the inner workings of the SIL system and interpreting the native tongue. Many thanks also to Nanna for the halibut dinners! Kristjan Ágústsson, Ragnar Stéfansson and the rest of SIL crew, thanks for having me around. The yearly excursions with the amateur glaciologists and Richard, Ásta and Halla were lots of fun.

Back at the department in Uppsala, Christopher Juhlin answered endless questions about the Siljan drilling operations and thoroughly reviewed both my first and second paper. Many thanks for the commas, Chris! Laust B. Pedersen guided my first steps into geophysics, showed me the intricacies of tellestrial electromagnetics and sent me of to Stanford with the Siljan FMS tapes. A job well done, and thanks for letting me stray off into seismology when I got home! Thanks also to Laust and Roland Roberts, who scrutinized the summary part of this thesis. For scientific discussions, and not so scientific discussions, I thank all the teachers and researchers at the department! Conny Holmqvist and I spent some memorable moments together in the Kurravaara winter, I'm still thawing my toes. Hasse Palm and Lars Dynesius started teaching me how to do seismic reflection field work, but gave up on me when I showed affections for passive sources.

What would you do without fellow students? Probably, you would finish in half the time and with a much cleaner vocabulary! But, what fun would that have been? Thanks guys! Siggi, Are and Nikke for showing me the real reason why lunch at Stockholms is soooo much better than elsewhere. Johannes, Niklas and Lena, for educating me by always having another question. Skånepågarna for convincing me that Roskilde 1658 was a major mistake (although a bottle of Glenlivet does make up for a lot, Stefan). Puy for an endless fountain of optimism and who, together with Los Amigos de Centro America, tried to keep up my Spanish. The Persians for help and friendship, Sverker for taking over all my responsibilities (have fun!) and my old students; Lill-Björn, Kattis, the Gun, Matilda and the rest, for the nerve-wrecking introduction to teaching.

The 13 months I spent at Stanford University did wonders for my knowledge of geophysics. Do you know there's a world out there?! Thanks to the Fulbright Commission for the grant, to Simon Klemperer for taking me on and to Mark Zoback for getting me out on the other end. Special thanks to Mark for teaching me how to write a paper, ``I like your data analysis Björn, but the paper is a near complete disaster.'', followed by pages of good advice. Big thanks to my friends in the seismic group, the borehole group and all the guys who started when I did. Special ``Hei'' to Per for the late night visits to the coffee shop. Shirin Ahlbäck and Maria Holmgren-Troy appeared one day on a Fulbright pass, full of enthusiasm and energy which was just what I needed at that time, thanks! Pete Brownell and the Biorockhuggers, what can I say? No matter what the geologists think, a good granite is a vertical granite! Thanks for taking me to the Valley and thanks for hanging on!

Fysik-kemisterna, thanks for showing the way. You made it look so easy!

There are friends, and then there are friends. I am very happy that they did not teach chemistry at the gymnasium in Katrineholm! Thanks for cheering me on Danne and for friendship and hospitality from you and Helena over the years.

Encouragement, support and a gentle kick in the behind. That's what family is for. You did it, it finally looks like I'm going to finish school! Thanks everybody for bedtime stories and homes away from home. Thanks Elisabeth and Carina for being sisters.

Two geophysics PhDs in the family. This could mean a down to earth life style but considering your involvement with explosion seismics, hmmm, I don't know. I thought the joint thesis writing could get tough, but you even enjoyed it! Thanks for being here Lena.