The invention relates to acquiring seismic data from the earth using geophones that are tuned to have differing frequency sensitivity ranges. From such index data, meshes are used to define an area based on the extent of a user’s living area around a retrieval center such as a current position, for example. The MRAM bit cell further includes a pass gate assembly connected to the first MTJ and the second MTJ, wherein the pass gate assembly comprises a plurality of transistors, and each transistor of the plurality of transistors is configured to selectively connect the first MTJ and the second MTJ to a driving line. A blower and filter unit provides air to the toxic free area to maintain an over pressure therein, ensuring that all entry to the toxic free area is through a flow of clean air.