@article{316f4a4fc6894663b792221f4fd0daac,
title = "My journey to the center of the Earth: A tribute to Professor Donald V. Helmberger",
author = "Song, {Xiao Dong}",
note = "On July 7, 1989, I arrived at Caltech. It was a Friday afternoon after work, time for the Division beer gathering at the back yard of the South Mudd Building. Lianshe picked me up at LAX (Los Angles International Airport) and we went straight there, where I instantly found that my earlier practice of oral English was quite useful in helping adapt to the new life. As I arrived early, I was supported by Clarence Allen for the summer months before the Fall quarter started. Prof. Allen was an old friend to Chinese geologists and geophysicists. He served in the Army Air Corps in the Pacific during World War II and visited China many times later on. At the beginning of the Fall semester, I was told that the Run Run Shaw Foundation (of Hong Kong) would offer me a 3-year graduate fellowship (given to only two Caltech graduate students that year), for which I could not think of a good reason except perhaps I did well in my TOEFL exam. Illinois at Urbana-Champaign, and visiting positions and recent full-time position in China. I{\textquoteright}ve received virtually continuous support in this study area over the decades from the U.S. National Science Foundation, the National Natural Science Foundation of China, the U.S. National Aeronautics and Space Administration, and so on. At the heart of the issue is the limited sampling and resolution of the core, particularly the inner core. For half of the century after its discovery, the inner core had been a featureless sphere. However, over the last few decades, it has been shown to be quite complex and mysterious. I was fortunate to start working on this problem at the cusp of important breakthroughs under Don{\textquoteright}s mentorship.",
year = "2022",
month = feb,
doi = "10.1016/j.eqs.2022.01.007",
language = "English (US)",
volume = "35",
pages = "34--39",
journal = "Earthquake Science",
issn = "1674-4519",
publisher = "KeAi Communications Co",
number = "1",
}