“Fire and Ice and Sinking Cities: Geology Now!” with Dr. Tony Waltham

Dr. Tony Waltham: Retired Senior Lecturer, University of Nottingham, UK, Award-Winning Geologist, Author, and Lecturer

Monday, January 12, 2026, 3:00-4:00 pm

To be followed by informal discussion.

Koffler Great Room at ASA and Zoom

13715 E. Langtry Lane

After a rich career of geological research around the world and lecturing at the University of Nottingham on mining and engineering geology, Tony Waltham is sharing his expertise and adventures with diverse audiences, including the passengers on Viking Cruise Lines’ Ocean Voyages. Between trips, he’s coming to ASA for a special series of lectures and discussions on geology illustrated with his own spectacular photographs.

In his first lecture, Dr. Waltham will discuss different kinds of volcanoes with different eruption styles, using Italy as his example. These avenues to the inside of the Earth are endlessly fascinating to us. Dr. Waltham begin with Sicily’s Mt. Etna, Europe’s most active large volcano, which many of us are lucky enough to have seen “spouting” on Mediterranean cruises. Off the north coast of Sicily, Stromboli is famous for its frequent modest eruptions, while nearby Vulcano has become a tourist attraction! Further north, Vesuvius is currently quiet but has produced great eruptions in the past, especially during that hyperactive 24 hours in AD 79. On the other side of Naples, Campi Flegrei is perhaps the least known but potentially the most devastating of the nation’s eruptive hot-spots.

Italy Volcanoes
Photo Credit: Tony Waltham

Volcanoes of Italy
Photo Credit: Tony Waltham

Jan 13: “Sinking Cities”

Dr. Tony Waltham: Retired Senior Lecturer, University of Nottingham, UK, Award-Winning Geologist, Author, and Lecturer

Tuesday, January 13, 2026, 3:00-4:00 pm

To be followed by informal discussion

Koffler Great Room at ASA and Zoom

In the second of his lectures, Tony Waltham will take up regional subsidence, a topic of concern to all the great coastal cities of the world—as well as inland cities such as Phoenix AZ. Subsidence, where a large part of a city slowly descends to lower levels, is almost always due to excessive groundwater extraction, with declining water tables. Dr. Waltham will explain how water abstracted from beds of sand drains water from adjacent beds of clay. The clays then compact, with the extent of ground subsidence depending on the clay type, its thickness, and the amount of water table decline. Mexico City holds the records for the amount of subsidence, and Jakarta currently has the greatest rate of sinking. Interestingly, Venice has subsided very little, but its critical position virtually at sea level has demanded unusual remedies and expensive engineering works.

Jan 14: “Greenland the Beautiful”

Dr. Tony Waltham: Retired Senior Lecturer, University of Nottingham, UK, Award-winning Geologist, Author, and Lecturer

Wednesday, January 14, 2026, 3:00-4:00 pm

Reception to follow

Koffler Great Room at ASA and Zoom

13715 E. Langtry Lane

In his third and final lecture, Tony Waltham will take us to Greenland, an Arctic wilderness he calls “fascinating, spectacular, and truly beautiful.” Is has recently become a place of great interest to US citizens, since our current president has vowed to acquire it, although it is—apparently happily– an autonomous region of Denmark. Largely covered by a huge and featureless ice sheet, the coastal margins of Greenland present glorious landscapes of bare rock and sparkling glaciers. A scatter of small and isolated communities of wooden houses painted in bright colors stand against backdrops of jagged mountains and passing icebergs. Few people venture onto the “Inland Ice,” a vast and alien environment. At lower altitudes, there are farms on green pastures around some of the southern fjords, where the first Viking settlers arrived and called it a “Green Land.” Further north, the dominant terrain type is bare rock. In the discussion, we may learn why the US should suddenly want to take over this enormous and mysterious land mass.