Marcus began working at the island's weather station in 1976. The facility is funded by the UK Met Office, and he has been station manager since 1992.
Responsibilities at the station include releasing a weather balloon into the atmosphere each day at precisely 11.15. Data transmitted from measuring equipment attached to the balloon is fed back to the UK.
This 'upper-air observing technique' requires the balloon to be filled with hydrogen, making the exercise potentially dangerous. The mask and goggles are to reduce static. The goggles also protect the eyes in the event of an explosion.
Jon Tonks' series 'Empire' follows his journey across the South Atlantic, exploring life on four remote islands - the British Overseas Territories of Ascension Island, Tristan da Cunha, the Falkland Islands and St. Helena - relics of the once formidable British Empire, all intertwined through their shared history.
Travelling 60,000 miles around the Atlantic over six years, Tonks spent up to a month at a time in each territory, documenting these landscapes, and within them, traces of imperial history. Writing about the series, Christopher Lord describes Tonks as hinting at 'a skewed vision of an older, distant but not-quite-departed Britain'.