Subaqueous geomorphology: options, tasks, needs

The purpose of the paper is to present the potentialities of current non-invasive methods for bottom surveys, including cartometric presentation of its relief and structure in both marine and inland reservoirs. The paper presents examples of results obtained in the Maritime Institute in Gdańsk during surveys carried out at the bottom of seas, lakes and rivers with the use of the same apparatus: primarily, a multibeam echosounder (MBES) to obtain a digital terrain model (DTM); a side-scan sonar (SSS) to obtain a general image of the nature of the bottom (its “roughness”); and seismic profiling (sub-bottom profiler, sediment echo sounder [SES]) to recognise the structure of the bottom. The obtained results constitute a necessary basis for carrying out further specialist surveys (non-invasive or invasive) when needed. Current bottom survey options that use MBES, SSS and SES may be treated as subaqueous equivalents of the subaerial potentialities of a land surface survey using LiDaR and GPR (Ground Penetration Radar)

Palaeo-valleys in the region of the Słupia River mouth

Basing on results of detailed hydroacoustic research, the geological structure of the bottom to 20–22 m b.s.l. has been studied. The palaeo-Słupia palaeo-valley, buried by a thin cover of marine sands, has been recognized and determined. Some stages of valley development may be distinguished. The deposits of the oldest valley are C14 dated at ca. 21 ka BP. But in the main stage, the valley was formed by action of the subglacial and thawing glacial waters during and after the so-called Gardno Phase. Most probably this valley was connected with the Pomeranian ice margin valley. The next stages of the valley’s development were related with changes of the palaeo-Słupia under conditions of the Litorina transgression. The youngest palaeo-Słupia valley is, in the authors’ opinion, related with a shallow, long incision, weakly marked in the sea bottom in the central part of the studied area. Field investigations were carried out by the Department of Operational Oceanography of the Maritime Institute in Gdańsk from the r/v Dr Lubecki. A DESO 15 echosounder, Subbottom Profilers model 3010 and the X Star system were used. Eight vibrocores (core length up to 3 m) were taken from the sea bottom and three borings (10–17 m depth) were executed on the shore. Accurate positioning was obtained using the DGPS and HYDRO and Track Point Systems. All data were digitally recorded and processed

Professor Piotr Roniewicz (1936-2019) In memoriam

Piotr Roniewicz was born in 1936 in Warsaw, however his family roots were in Stanisławów (nowadays Ivano-Frankivsk, Ukraine). He completed his university studies at the Faculty of Geology of the University of Warsaw in 1959, gaining a Master’s Degree. He began his geological career at this Faculty already as a 4th year student. In 1981-1984 he was the Vice-Dean and later in 1984-1990 – the Dean of the Faculty. Professor Roniewicz worked there until his retirement in 2006