Contrasting Seismic Velocity and Compaction of Marine Calcareous Oozes and Volcaniclastic Deposits on the South Aegean Volcanic Arc

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F25%3A10503699" target="_blank" >RIV/00216208:11310/25:10503699 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=NxPIrLqDQh" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=NxPIrLqDQh</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2025GC012327" target="_blank" >10.1029/2025GC012327</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Contrasting Seismic Velocity and Compaction of Marine Calcareous Oozes and Volcaniclastic Deposits on the South Aegean Volcanic Arc

Popis výsledku v původním jazyce

International Ocean Discovery Program Expedition 398 recovered more than 2,200 m of volcaniclastic deposits from 12 sites and 28 holes from Santorini Caldera, Greece, and the surrounding rift basins in the South Aegean Volcanic Arc. We compare and contrast discrete shipboard measurements of physical properties (density, P-wave velocity) of these volcaniclastic sediments with other uncemented marine sediments in the cores. The grain density (mass of solids divided by their volume, including any isolated vesicles) of volcaniclastic deposits is typically lower than that of volcanic glass and crystals and is sometimes less than 2 g/, indicating the preservation of isolated gas-filled vesicles in erupted materials. Volcaniclastic deposits typically have higher P-wave velocities but lower bulk densities than oozes and other marine sediments. In volcaniclastic deposits, lapilli have higher P-wave velocities and lower bulk density than ash, the opposite trend of most sediment in which higher density is correlated with higher seismic velocity. We use granular physics models to show that the higher volcaniclastic P-wave velocity originates from two effects: (a) lower pore volume outside clasts that increases elastic moduli and (b) isolated gas vesicles in volcanic clasts that lower bulk density. In volcaniclastic sediments there is relatively little change in physical properties to depths of several hundred meters below the seafloor, which we attribute to rough grain surfaces and lower intergranular (external) porosities that hinder compaction and the decrease of intergranular pore space. These trends lead to distinctive signatures of volcaniclastic sediments in reflection seismic images.

Název v anglickém jazyce

Contrasting Seismic Velocity and Compaction of Marine Calcareous Oozes and Volcaniclastic Deposits on the South Aegean Volcanic Arc

Popis výsledku anglicky

International Ocean Discovery Program Expedition 398 recovered more than 2,200 m of volcaniclastic deposits from 12 sites and 28 holes from Santorini Caldera, Greece, and the surrounding rift basins in the South Aegean Volcanic Arc. We compare and contrast discrete shipboard measurements of physical properties (density, P-wave velocity) of these volcaniclastic sediments with other uncemented marine sediments in the cores. The grain density (mass of solids divided by their volume, including any isolated vesicles) of volcaniclastic deposits is typically lower than that of volcanic glass and crystals and is sometimes less than 2 g/, indicating the preservation of isolated gas-filled vesicles in erupted materials. Volcaniclastic deposits typically have higher P-wave velocities but lower bulk densities than oozes and other marine sediments. In volcaniclastic deposits, lapilli have higher P-wave velocities and lower bulk density than ash, the opposite trend of most sediment in which higher density is correlated with higher seismic velocity. We use granular physics models to show that the higher volcaniclastic P-wave velocity originates from two effects: (a) lower pore volume outside clasts that increases elastic moduli and (b) isolated gas vesicles in volcanic clasts that lower bulk density. In volcaniclastic sediments there is relatively little change in physical properties to depths of several hundred meters below the seafloor, which we attribute to rough grain surfaces and lower intergranular (external) porosities that hinder compaction and the decrease of intergranular pore space. These trends lead to distinctive signatures of volcaniclastic sediments in reflection seismic images.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geochemistry, Geophysics, Geosystems

ISSN

1525-2027

e-ISSN

1525-2027

Svazek periodika

26

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

20

Strana od-do

e2025GC012327

Kód UT WoS článku

001577598300001

EID výsledku v databázi Scopus

2-s2.0-105021466241