Description: Hydrothermal activity along Mid–Ocean Ridges is dominated by high–temperature venting mostly confined to ridge axis and neotectonic zone extending ~15km on each side of the axis. However, extensive exploration and discoveries of new hydrothermal fields in off–axis regions (e.g. Lost City, MAR) show that hydrothermal activity may be dominated by off–axis venting. Hence, little is known about controls and nature of such systems, for example, weather low–temperature “diffuse” venting dominates? Such systems may transport even 90% of hydrothermal heat to the oceans. This makes them a great potential source of renewable energy. However, we need to know where to look for them on the seafloor? On Iceland 95% of hydrothermalism takes place through low-temperature venting, therefore as subaerial part of the Mid-Atlantic Ridge, Iceland can help us better understand underwater hydrothermalism. Unfortunately, the technology to detect these systems is rudimentary. Therefore we need to develop an inexpensive and precise method for detecting low-temperature venting that will have very little impact on environment but will help us accurately assess potential of these systems. Observations of Icelandic systems helped me to develop predictive model for locating low-temperature venting on the Reykjanes Ridge (south of Iceland) based on existing bathymetry maps. This method could potentially be applied to other mid-ocean ridges worldwide. Seafloor of Reykjanes Ridge is easy to reach due to shallow depth. With high resolution maps we can focus investigations to pre-targeted areas of interest. Biological observations can significantly improve this method since detecting signals created by low-temperature fluids is very difficult with only geological, acoustic and optic measurements. Visual observations of bacteria mats or mussels (e.g. Bathymodiolus) can help directly locating sites where fluids escape from the crust.