In March 2021, a six-month eruption began in the Geldingadalir valley in Iceland, characterised by effusion episodes and lava fountains. On 8 June 2021, the active crater featured an active lava pond with episodic lava pond fluctuations. To analyse the eruption on this day in June, we used a seismometer from the University of Cambridge to measure the tremor duration, repose time and amplitude on this day in June. In addition, we used high-resolution videos and images captured by UAS from the German Research Centre (GFZ) in Potsdam, which allowed us to create a digital elevation model (DEM) and an orthomosaic to estimate the lava pond level over time and the diameter of the boiling area. The data used in this study, including videos, DEM, orthomosaic, and a marker file of the start and end of the tremor episodes, are publicly available