A tri-axis accelerometer for use in seismic surveying is provided. The accelerometer comprises at least three fiber optic accelerometer elements which have respective fiber sensor coils, and which are characteristic in that the fiber sensor coils are coiled about a common coiling axis and at least one of the accelerometer elements is a slant angle accelerometer element. A corresponding method of manufacturing a tri-axis fiber optic accelerometer is also disclosed. A fiber optic tri-axis accelerometer for sensing acceleration in three directions is also provided, which comprises a first, a second, and a third sensor base, each base including a first, a second, and a third fixed element, respectively, and a first, a second, and a third movable element, respectively, each pair of fixed and movable elements carrying a fiber sensing coil. The fiber sensing coils are all coiled around a common coiling axis and at least one of the movable elements is designed and mounted so as to be movable in a direction that is slanted with respect to the common coiling axis.