From January 25 to 30, a visit was paid by Professor Eric Ivan Thorsos of the Applied Physics Laboratory, University of Washington (UW-APL) to the First Institute of Oceanography (FIO).

During the exchange visit, Professor Thorsos delivered two academic reports respectively entitled "Reverberation measurements and modeling at mid-frequency", and "Frequency dependence of sound speed and attenuation in sandy sediments". Professor Thorsos detailed the latest developments of UW-APL in mid-frequency acoustic scattering in sea interface, shallow water reverberation model, frequency dependence of sound speed and attenuation in sandy sediments and its prediction models. He also introduced the newest research progresses in sediment acoustic properties and prediction models reported at the recent annual meeting of the Acoustical Society of America (ASA). The researchers of the Sediment Acoustics Research Team of FIO respectively made several academic reports entitled "Geoacoustic experiment and sound speed dispersion at low-mid frequency at fine-grained sediment", "Laboratory measurements of sound speed and attenuation dispersion in calcareous sediments from coral reefs", "Comparison of acoustic backscattering from a sandy and a silty bottom in the South Yellow Sea of China", and "Acoustic backscattering measurement from sea surface at 6-24 kHz in the Yellow Sea." They elaborated FIO's latest achievements in sediment acoustic properties and models, and the properties and models of acoustic scattering at middle frequency at bottom and sea surface.

This academic exchange has played a positive role in promoting FIO's researches on sediments acoustic properties and modeling. The two parties have reached a preliminary cooperation intention on studying the low-to-mid frequency acoustic properties and models at fine-grained sediments and the properties of three-dimensional mid-frequency acoustic scattering at sea surface in the future.