A pressure-balanced seismic sensor package, comprising: a plurality of optical components (106, 206, 506, 552, 554), wherein the plurality of optical components (106, 206, 506, 552, 554) comprises an optical accelerometer (106, 206, 506); a sensor box with an interior to enclose the plurality of optical components (106, 206, 506, 552, 554) and comprising: a first compartment (102, 502, 902) housing the optical accelerometer (106, 206, 506) of the plurality of optical components (106, 206, 506, 552, 554); and a second compartment (104, 504, 904) separated from the first compartment by a dividing wall (103, 203, 503, 903), and housing a second optical component of the plurality of optical components (106, 206, 506, 552, 554); the pressure-balanced seismic sensor package being characterized in that it further comprises a lid (109, 409, 909) for the sensor box, comprising: a first flexible component (428-1, 928-1) formed in a first portion of the lid (109, 409, 909) over the first compartment (102, 502, 902); and a second flexible component (428-2, 928-2) formed in a second portion of the lid (109, 409, 909) over the second compartment (104, 504, 904), wherein the first (428-1, 928-1) and the second (428-2, 928-2) flexible components are formed to contribute to a pressure-balance of the sensor box by an alteration of shape of the first (428-1, 928-1) and the second (428-2, 928-2) flexible components in response to a change in an external pressure. a plurality of optical components (106, 206, 506, 552, 554), wherein the plurality of optical components (106, 206, 506, 552, 554) comprises an optical accelerometer (106, 206, 506); a sensor box with an interior to enclose the plurality of optical components (106, 206, 506, 552, 554) and comprising: a first compartment (102, 502, 902) housing the optical accelerometer (106, 206, 506) of the plurality of optical components (106, 206, 506, 552, 554); and a second compartment (104, 504, 904) separated from the first compartment by a dividing wall (103, 203, 503, 903), and housing a second optical component of the plurality of optical components (106, 206, 506, 552, 554); the pressure-balanced seismic sensor package being characterized in that it further comprises a lid (109, 409, 909) for the sensor box, comprising: a first flexible component (428-1, 928-1) formed in a first portion of the lid (109, 409, 909) over the first compartment (102, 502, 902); and a second flexible component (428-2, 928-2) formed in a second portion of the lid (109, 409, 909) over the second compartment (104, 504, 904), wherein the first (428-1, 928-1) and the second (428-2, 928-2) flexible components are formed to contribute to a pressure-balance of the sensor box by an alteration of shape of the first (428-1, 928-1) and the second (428-2, 928-2) flexible components in response to a change in an external pressure. a first compartment (102, 502, 902) housing the optical accelerometer (106, 206, 506) of the plurality of optical components (106, 206, 506, 552, 554); and a second compartment (104, 504, 904) separated from the first compartment by a dividing wall (103, 203, 503, 903), and housing a second optical component of the plurality of optical components (106, 206, 506, 552, 554); the pressure-balanced seismic sensor package being characterized in that it further comprises a lid (109, 409, 909) for the sensor box, comprising: a first flexible component (428-1, 928-1) formed in a first portion of the lid (109, 409, 909) over the first compartment (102, 502, 902); and a second flexible component (428-2, 928-2) formed in a second portion of the lid (109, 409, 909) over the second compartment (104, 504, 904), wherein the first (428-1, 928-1) and the second (428-2, 928-2) flexible components are formed to contribute to a pressure-balance of the sensor box by an alteration of shape of the first (428-1, 928-1) and the second (428-2, 928-2) flexible components in response to a change in an external pressure. a first flexible component (428-1, 928-1) formed in a first portion of the lid (109, 409, 909) over the first compartment (102, 502, 902); and a second flexible component (428-2, 928-2) formed in a second portion of the lid (109, 409, 909) over the second compartment (104, 504, 904), wherein the first (428-1, 928-1) and the second (428-2, 928-2) flexible components are formed to contribute to a pressure-balance of the sensor box by an alteration of shape of the first (428-1, 928-1) and the second (428-2, 928-2) flexible components in response to a change in an external pressure.