"A New Map of Earthquake Distribution", by Captain Nicholas Heck, U. S. Coast
and Geodetic Survey. In: The Geographical Review, Vol. XXV, 1935. Pp. 125-130.
Heck noted for the first time that earthquakes were associated with the Mid-
Atlantic Ridge in his accompanying paper. Heck first produced a world seismicity
map showing the activity on the Mid-Atlantic Ridge in 1932.