def extend_to_depth(interps, maxk=35):
    """Fill all values below level with LiveOcean data with data from above
    start at maxk

    :arg interps: dictionary of 3D numpy arrays.
                  Key represents the variable name.
    :type interps: dictionary

    :arg maxk: maximum Live Ocean depth with data
    :type maxk: int

    :returns interps extended to depth
    """

    for var in interps.keys():
        interps[var][maxk:] = interps[var][maxk - 1]

    return interps