What is the author's style in Endurance: Shackleton's Incredible Voyage by Alfred Lansing?

The historical text is written from the perspective of some decades after the events described. It is presented in a typical journalistic third-person, limited, point of view. The infrequently presented interior thoughts or motivations of individuals are not created from whole cloth but instead derived from analysis of journal entries and personal interviews with survivors. Indeed, the source materials available to the author are incredibly complete and a list of acknowledgements and primary sources are offered at the end of the text.