EES Geoscience Seminar Series: Susan Meerdink (UIowa - Geographical & Sustainability Sciences) & Valerie Payre (Earth & Environmental Sciences)

Feb 9, 2024

03:30 PM - 05:00 PM

Gilmore Hall, 106 GILH

112 South Capitol Street, Iowa City, IA 52240

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Dr. Susan Meerdink: "Monitoring dynamics of invasive plants using remote sensing and machine learning tools"
Invasive plant species remain one of the primary threats to ecosystems because they alter critical ecosystem functions and suppress native species' ability to respond to changes in environmental conditions. Accumulation of invaders is projected to increase over the next two decades. Detection and long-term monitoring of invasions provide valuable ecological information and ultimately guide management decisions. One of the challenges of managing invasives across landscapes is determining where they are located, particularly at the early stages of an invasion, where they occur at low densities mixed with native vegetation. Traditional surveys through ground efforts are often infeasible due to cost and logistics, especially when considering repeat surveys are needed to determine spread. Remote sensing could improve response to invasions by providing accurate and affordable repeat imagery as a more cost-effective way to monitor spread. This research explores our ability to detect invasives using multi-spectral remote sensing and a machine-learning approach adapted to detect invasives at low densities with imprecision in the dataset. Here we show data from the Everglades National Park, which presents an ideal case study for using remote sensing to capture invasive species spread because the majority of the park is accessible only by watercraft or helicopter, making monitoring and managing invasive plant populations exceptionally difficult and costly.

Dr. Valerie Payre: "Unraveling Mars' Crustal Evolution: Use of Remote Sensing and Experimental Petrology"
The geology of planetary bodies, especially in the inner Solar System, is mainly studied by remote sensing with mid-infrared (MIR) and visible/near infrared (VNIR) spectrometer onboard spacecrafts. The discovery of complex impacted surfaces, especially in the igneous realm, demonstrated that although spectroscopy allow to decipher the mineralogy of planetary surfaces, many minerals cannot be detected, leading to debates and misinterpretations of the nature of outcrops. On Mars, the finding of felsic rocks by the Curiosity rover and feldspar-rich rocks from VNIR orbital spectroscopy was an excitement for the planetary community since Mars’ crust, thought to be a basaltic world, might actually be dichotomic with possible felsic and mafic components. The lack of high-resolution images and remote sensing instrument limitations prevent a characterization of these feldspar-rich outcrops, suggested in the literature to be either feldspar-rich basalts, anorthosites, feldspar cumulates, granites, or felsic lava flows. The magmatic implications of each of these rocks are distinct, and unraveling their petrology is therefore essential to untangle the petrology and complexity of the Martian crust. Laboratory analyses on martian igneous samples, analog samples, and various mineral mixtures are necessary to better constrain the limitations of remote sensing and assess the petrology of igneous terrains, which will be a work presented in the talk. I will present a helicopter concept mission that will be proposed next year to NASA to fly over feldspar-rich outcrops and characterize their petrology. The occurrence of felsic rocks on Mars has been a surprise and even though many igneous processes can explain their formation, an onset of plate tectonic is also a possibility that will be discussed in the talk. The seminar is a summary of the research conducted by the undergraduate and graduate students of the Planetary Exploration Group in the EES department. Petrography observations, laboratory spectral results, experimental work, as well as orbital VNIR and rover data will be presented to provide insights into the complexity of Mars’ crust and its evolution through time and space.

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