photo of an iceberg

Geology Lecture: Revealing Rhythms of Ice Ages with Paleomagnetism

Anne Matthews News

Coos Bay, OR – Southwestern Oregon Community College’s popular Geology Lecture Series continues for the 2021-22 academic year with the lecture “Revealing Rhythms of Ice Ages with Paleomagnetism”, by Dr. Brendan Reilly (Scripps Institution of Oceanography) at 7:00 p.m., Tuesday, November 9, via Livestream from the College’s website:

The lecture will be viewed live online with a Q & A session with the speaker following the talk. Advance questions may be sent to Ron Metzger at [email protected].  

Paleomagnetism is the study of the record of the Earth’s magnetic field in rocks, sediment, or archeological materials. For over 50 years, the International Ocean Discovery Program (IODP) and its predecessor programs have recovered and archived long sedimentary records of Earth’s climate and geomagnetic histories for international scientific study. State of the art shipboard laboratories now allow for the rapid collection of non-destructive data that provide initial characterization of sediment lithologic variations and paleomagnetic history within hours of sediment core recovery. Scientific ocean drilling records have revealed several significant shifts in Earth’s climate state over the last 3.5 million years, including the initiation of expanded bipolar glaciation and changes in the amplitude and frequency of global ice volume variations. Over this time, it is long accepted that the rhythms of ice age cycles are set by periodic variations in Earth’s orbit.  

In 2019, IODP drilled Antarctic proximal sediments in the Scotia Sea’s “Iceberg Alley” during Expedition 382, recovering an expanded sedimentary sequence from a region influenced by Antarctic Ice Sheet history and Southern Ocean dynamics. In this talk, Dr. Reilly will highlight these new Iceberg Alley records and discuss how their rhythms are both similar and different to the well-established rhythms of ice age cycles that have been defined by geochemistry using oxygen isotope data.

Dr. Reilly earned his Ph.D. at Oregon State University and is a Postdoctoral Researcher at the Scripps Institution of Oceanography in San Diego and the Co-Chief scientist of the Cascadia High-Resolution Observations of Paleo Systems (H.O.P.S.) expedition. He has worked globally on the stratigraphy, paleomagnetism, and chronology of sediment cores from offshore Antarctica to Northern Greenland. Future projects for his team include a focus on a lengthy record of environmental, oceanographic, ice sheet, tectonic and geomagnetic change recorded in the offshore sediments of the Pacific Northwest. 

All lectures in the series are free. Future talks this year include: The 17th Annual Cascadia Anniversary Lecture with Dr. Chris Goldfinger (Oregon State University) on Wednesday, January 26th at 7:00 pm; and Dr. Sean Davis (NOAA) on Tuesday, February 8 at 7:00 pm with “Lessons at the school of hard knocks: from the ozone hole to global climate change” both via Livestream. We hope to be back to live presentations spring 2022. All talks are archived for later viewing.  

Lecture series sponsors include: DB Western, Southwestern Foundation, The Mill Casino, Ocean Discovery Lecture Series, and the College. For additional information (or to submit questions prior to the talk) contact Ron Metzger at [email protected] or 541-888-7216.