Pika Vent



Latitude: 12.9187οN                Longitude: 143.6487οE                       Depth: 2774 m bsl

The Pika site is located on the top of an off-axial seamount (Ishibashi et al., 2006), and was identified as localities created by long-term hydrothermal activity (Yoshikawa et al., 2012). The seamount is composed of pillow lavas with minor sediment covers while there are several discrete vents with active and inactive sulfide chimneys (Kakegawa et al., 2008). The highest observed temperature of the black smoker was 330 °C (Yoshikawa et al., 2012) while the fluids are rich with Cl, Fe (Ishibashi et al., 2006) and H2S (Kato et al., 2010) and has a low pH (Ishibashi et al., 2006). The biodiversity around the Pika site include several bacterial species as well as barnacles, shrimp and snails (Kato et al., 2010; Kato et al., 2012; Kumagai et al., 2015).

Table 1: Operations history for Pika vent

Ship/ Platform Operation Year Dive Number References
Hakurei-Maru #2 cruise BMS (Benthic Multi-coring System) 2004 January Not found YK05-09-Leg2
Yokosuka Cruise 05-09 Shinkai 6500 2005 July-August 906 YK05-09-Leg2
Yokosuka Cruise 10-11 Shinkai 6500 2010 September 1222, 1225, 1226 YK10-11 cruise report
Yokosuka Cruise 10-10 Shinkai6500 2010 August 1214

YK10-10 cruise report

Table 2: Vent activity and host rocks

Activity and host rocks References
Activity Active Kato et al., 2010
Host Rocks Tholeiitic andesite Kakegawa et al., 2008

Table 3: Vent fluid characteristics

Vent Fluids References
Temperature (οC) 315 οC -330 οC Baker et al., 2005; Ishibashi et al., 2006
pH 3 at 25 οC


Ishibashi et al., 2006

Toki et al., 2015

Composition Metal rich, high Cl concentration and low pH Ishibashi et al., 2004

Kakegawa et al., 2008

CO2 (mM) 33.7-69.1 Toki et al., 2015
H2 (μM) 301 Toki et al., 2015
Mn (mM) 1.13 Toki et al., 2015
Fe (mM) 7.38 Toki et al., 2015
He (μM) 1.83 Toki et al., 2015
CH4 (μM) 7.2-29.9μ Toki et al., 2015

Table 4: Vent Biology

General name Phylum Class/Order Family Genus/Species References
Bacteria Aquificae Aquificales Hydrogenothermaceae Persephonella Kato et al., 2012
Bacteria Proteobacteria Gammaproteobacteria Thiomicrospira Kato et al., 2010;  Kato et al., 2012
Bacteria Proteobacteria Epsilonproteobacteria Campylobacterales Hydrogenimonas Kato et al., 2010;  Kato et al., 2012
Bacteria Proteobacteria Epsilonproteobacteria Campylobacterales Sulfurimonas Kato et al., 2010; Kato et al., 2012
Bacteroidetes Kato et al., 2010
Bacteria Proteobacteria Zetaproteobacteria Mariprofundus Kato et al., 2012
Barnacles Arthropoda Multicrustacea Neoverrucidae Neoverruca brachylepadoformis Kumagai et al., 2015
Shrimp Arthropoda Malacostraca Alvinocarididae Chorocaris vandoverae Kumagai et al., 2015
Snail Mollusca Gastropoda Provannidae Alviniconcha hessleri Kumagai et al., 2015


  1. J-EDI JAMSTEC E-Library for Deep-sea: note: search “Pika”.

Video Links:

  1. J-EDI JAMSTEC E-Library for Deep-sea: note: search “Pika”.


  1. Baker, E. T., Massoth, G. J., Nakamura, K., Embley, R. W., de Ronde, C. E. J., and Arculus, R. J., 2005. Hydrothermal activity on near-arc sections of back-arc ridges: Results from the Mariana Trough and Lau Basin. Geochemistry, Geophysics, Geosystems 6 (9), doi: 10.1029/2005GC000948.
  2. Ishibashi, J., Suzuki, R., Yamanaka, T., Toki, T., Kimura, H., Noguchi, T., Urabe, T., 2006. Seafloor hydrothermal activity at offaxial seamounts of backarc spreading in southern Mariana Trough. Geochimica et Cosmochimica Acta 70 (18), A279-A279.
  3. Ishibashi, J., Yamanaka, T., Kimura, H., Hirota, A., Toki, T., Tsunogai, U., Gamo, T., Utsumi, M., Roe, K., Miyabe, S., Okamura, K. 2004. Geochemistry of Hydrothermal Fluids in South Mariana Backarc Spreading Center. American Geophysical Union, Fall Meeting 2004, abstract #V44A-05.
  4. Kato, S., Takano, Y., Kakegawa, T., Oba, H., Inoue, K., Kobayashi, C., Utsumi, M., Marumo, K., Kobayashi, K., Ito, Y., Ishibashi, J., Yamagishi, A., 2010. Biogeography and biodiversity in sulfide structures of active and inactive vents at deep-sea hydrothermal fields of the Southern Mariana Trough. Applied Environmental Microbiology 76 (9), 2968-2979.
  5. Kato, S., Nakamura, K., Toki, T., Ishibashi, J., Tsunogai, U., Hirota, A., Ohkuma, M., Yamagishi, A., 2012. Iron-based microbial ecosystem on and below the seafloor: a case study of hydrothermal fields of the Southern Mariana Trough. Frontiers in Microbiology 3, doi: 10.3389/fmicb.2012.00089. 13.
  6. Kumagai, H., Watanabe, H., Yahagi, T., Kojima, S., Nakai, S., Toyoda, S., Ishibashi, J., 2015. Evaluating Hydrothermal System Evolution Using Geochronological Dating and Biological Diversity Analyses. In: Ishibashi, J., Okino, K., Sunamura, M. (Eds.), Subseafloor Biosphere Linked to Hydrothermal Systems: TAIGA Concept. Springer Japan, 49-59.
  7. Toki, T., Ishibashi, J., Noguchi, T., Tawata, M., Tsunogai, U., Yamanaka, T., and Nakamura, K., 2015, Chemical and Isotopic Compositions of Hydrothermal Fluids at Snail, Archaean, Pika, and Urashima Sites in the Southern Mariana Trough. In: Ishibashi, J., Okino, K., Sunamura, M. (Eds.), Subseafloor Biosphere Linked to Hydrothermal Systems: TAIGA Concept. Springer Japan, 587-602.
  8. Yoshikawa, S., Okino, K., and Asada, M., 2012. Geomorphological variations at hydrothermal sites in the southern Mariana Trough: Relationship between hydrothermal activity and topographic characteristics. Marine Geology 303-306, 172-182.
  9. Kakegawa, T., Utsumi, M., and Marumo, K., 2008, Geochemistry of Sulfide Chimneys and Basement Pillow Lavas at the Southern Mariana Trough (12.55°N-12.58°N): Resource Geology 58 (3), 249-266.

Website References:

  1. JAMSTEC (Japan Agency for Marine Earth Science and Technology) E-library of Deep-sea Images (JEDI) (accessed 11/26/2015)

Cruise Reports:

  1. Yokosuka cruise report YK05-09-Leg2
  2. Yokosuka cruise report YK10-11
  3. Yokosuka cruise report YK10-10