In Situ Tech­no­lo­gi­en

The se­di­ment sur­face is cha­rac­te­ri­zed by steep gra­di­ents and an ex­ten­si­ve spa­ti­al and tem­po­ral he­te­ro­gen­ei­ty. Mea­su­re­ments with high tem­po­ral and spa­ti­al re­so­lu­ti­on are cru­ci­al for the un­der­stan­ding of ear­ly dia­ge­ne­sis, mi­cro­be-en­vi­ron­ment in­ter­ac­tions, and bent­hic flu­xes. To de­ter­mi­ne mi­cro­bi­al con­ver­si­on ra­tes in se­di­ments, and to get in­sights into their re­gu­la­ti­on, ac­tivi­ty mea­su­re­ments must be com­ple­men­ted by the cha­rac­te­riza­t­i­on of the ha­bi­tat, its mi­cro­en­vi­ron­ments, the de­ter­mi­na­ti­on of trans­port pheno­me­na, and sub­stra­te avail­a­bi­li­ty. The mi­cro­pro­fi­ler unit enables the in situ quan­ti­fi­ca­ti­on of such pro­ces­ses in en­vi­ron­ments whe­re core re­trie­val se­ver­ely al­ters the se­di­ment, such as in gas-la­den cold seeps, the deep sea, or high­ly dy­na­mic en­vi­ron­ments. more ...

In the high­ly he­te­ro­ge­neous oce­an eco­sys­tem, the se­di­ment-bot­tom wa­ter in­ter­face re­pres­ents a boun­da­ry zone that con­nects the two ocea­nic re­alms - the se­di­ment and the wa­ter co­lumn. At the seaf­loor, the se­di­ment-wa­ter in­ter­face is one of the most im­portant tran­si­ti­on zo­nes for so­lu­te ex­ch­an­ge, both in time and space. The bent­hic cham­ber mo­du­le enables in situ mea­su­re­ments of the to­tal ex­ch­an­ge ra­tes (e.g oxy­gen, me­tha­ne, nut­ri­ents, DIC) bet­ween the se­di­ment and the wa­ter co­lumn. This mea­su­re­ment in­te­gra­tes all re­le­vant so­lu­te trans­port pro­ces­ses (dif­fu­si­on, ad­vec­tion, and fau­na-me­dia­ted trans­port). more .....

The se­di­ment-wa­ter in­ter­face is one of the most im­portant boun­da­ry lay­ers of the earth sys­tem with cru­ci­al fil­ter func­tions for the mass ex­ch­an­ge bet­ween the seaf­loor and the wa­ter co­lumn. One of the most im­portant ex­ch­an­ge pro­ces­ses across this lay­er is the oxy­gen flux, which is a fun­da­men­tal con­trol fac­tor for the bio­geo­che­mi­cal ac­tivi­ty in the se­di­ment. The eddy cor­re­la­ti­on sys­tem (ECS) al­lows the mea­su­ring of ex­ch­an­ge ra­tes across the wa­ter-se­di­ment in­ter­face in a non-in­va­si­ve man­ner, pro­vi­ding di­rect mea­su­re­ments with tem­po­ral re­so­lu­ti­on of mi­nu­tes, and a spa­ti­al re­so­lu­ti­on of se­veral me­ters. more ....