Department or Program
Geology
Abstract
The Himalayan Mountains are a ~2500 km long seismically active mountain range formed due to the collision of the Indian and Eurasian lithospheric plates that presents great risk of earthquakes to the densely populated Indo-Gangetic Plain. The highly populated regions of Himalaya are primarily located near the active Himalayan Frontal Thrust (HFT), which has experienced multiple major (Mw 7.0-7.9) and great (Mw >8.0) earthquakes and thus present high seismic risk to the region. Additionally, the Central Seismic Gap is a section of the Himalaya which has a poorly understood rupture history. This undergraduate thesis focused on the AD1505 historical earthquake in Central Himalaya, for which magnitude and surface ruptures remain ambiguous. To achieve this objective, a trench was excavated within the Central Seismic Gap near Ramnagar, Uttarakhand. The radiocarbon samples collected from the stratigraphic units which bracket the events in Chorpani trench indicate that an initial event is exposed in the trench between AD1459 and AD1635, with a multi-event displacement of at least 7m. The second exposed event likely occurred between AD1736 and AD1919 and is thus attributed to the AD1803 earthquake. The findings of this thesis serve to better understand the lateral extent of the 1505 earthquake and overall Central Seismic Gap rupture history. The section of the HFT for which AD1505 earthquake ruptured has not experienced a surface rupture earthquake since and is therefore likely under high stress.
Level of Access
Restricted: Embargoed [Bates Community After Expiration]
First Advisor
Arora, Shreya
Date of Graduation
5-2023
Degree Name
Bachelor of Science
Recommended Citation
Meenan, Natalie, "A Paleoseismic Investigation of the Central Seismic Gap and Rupture Extent of the AD1505 Earthquake: Northwest Himalaya, India" (2023). Honors Theses. 440.
https://scarab.bates.edu/honorstheses/440
Number of Pages
66