Fig. 1

Schematics showing global distribution of cold seeps. The seeps from the northern Indian Ocean are mainly located in the region of Makran and Bay of Bengal (in the black dotted box). After Suess (2014)"

Fig. 2

Distribution of typical cold seeps in the northern India Ocean. Data from Mazumdar et al (2009), Himmler et al (2010, 2015), Fischer et al (2012), and Teichert et al (2014)"

Tab. 1

Information and brief description of cold seep sites in the Northern Indian Ocean"

Fig. 3

Active seeps of Makran (Bohrmann et al, 2008). (a) Abundant living mussels on carbonate pavements; (b) dense accumulations of mussels (Bathymodiolus platifrons) and crabs (Shinkaia crosnieri); (c) bacterial maps surrounding gas bubble escape sites; and (d) a bubble emanating spot"

Fig. 4

Geological record of cold seep activity in the Bay of Bengal. (a) Large authigenic carbonate nodules of sediments (Collett et al, 2008); (b) mudstone concretion with gas flow conduit (chimney)( Joshi et al, 2014); (c) fragment of Calyptogena sp. shell external surfaces (Joshi et al, 2014); and (d) possible fossil chemosynthetic communities in sediments (Collett et al, 2008)"

Fig. 5

Cold seep carbonates #cod#x003b4;13C, #cod#x003b4;18O (take Vienna Pee Dee Belemnite as a standard, abbreviated as VPDB) scatter plot of the northern Indian Ocean (von Rad et al, 1996; Mazumdar et al, 2009; Himmler et al, 2015; Kocherla et al, 2015)"

Fig. 6

Photographs of carbonates and seafloor at seeps inside and outside of Makran oxygen minimum zone. After Himmler et al (2015)"

Fig. 7

Pattern diagrams of cold seep activity triggered by earthquake. (a) Seabed model of pre-event; (b) seabed model of post-event; and (c) diagenetic Ba content and sulfate concentration of surface sediments. Dashed line represents pre-event, and solid line denotes post-event.After Fischer et al (2013)"