Video Experimental Relacionado
Updated: Mar 10, 2026
09:06
Removal of Exogenous Materials from the Outer Portion of Frozen Cores to Investigate the Ancient Biological Communities Harbored Inside
Published on: July 3, 2016
8.7K
Una capa de hielo de Groenlandia Oriental persistente y dinámica durante los últimos 7,5 millones de años
Paul R Bierman1, Jeremy D Shakun2, Lee B Corbett1
1Department of Geology and Rubenstein School of the Environment and Natural Resources, University of Vermont, Burlington, Vermont 05405, USA.
Nature
|December 9, 2016
Resumen
La capa de hielo de Groenlandia Oriental ha persistido durante millones de años, mostrando cambios dinámicos durante el Pleistoceno temprano y una extensa cubierta de hielo más tarde. Esto desafía las ideas de deglaciación completa en períodos cálidos pasados.
Área de la Ciencia:
- Paleoclimatología
- Glaciología
- Geoquímica marina
Sus antecedentes:
- Comprender el comportamiento pasado de las capas de hielo es crucial para predecir el aumento futuro del nivel del mar.
- Los registros terrestres de las antiguas capas de hielo a menudo se erosionan y son poco datados.
- Los sedimentos marinos ofrecen un registro más continuo de las variaciones de la capa de hielo.
Objetivo del estudio:
- Para reconstruir la historia de la capa de hielo del este de Groenlandia durante los últimos 7,5 millones de años.
- Investigar la dinámica de las capas de hielo durante las transiciones climáticas clave.
- Desafiar las suposiciones sobre la deglaciación completa durante los períodos interglaciales pasados.
Principales métodos:
- Análisis de los isótopos de berilio y aluminio (10Be y 26Al) en los sedimentos marinos.
- Utilizando núcleos cosmogénicos para rastrear la erosión glacial y el transporte de sedimentos.
- Interpretando las firmas isotópicas para inferir la extensión y actividad de la capa de hielo.
Principales resultados:
- La capa de hielo del este de Groenlandia ha existido continuamente durante al menos 7,5 millones de años.
- La cubierta de hielo fue dinámica en el Pleistoceno temprano y extensa durante el Pleistoceno medio a tardío.
- Los datos isotópicos se correlacionan con las principales transiciones climáticas, lo que indica cambios en el comportamiento de la capa de hielo.
Conclusiones:
- El estudio proporciona evidencia contra la deglaciación completa y extendida en el este de Groenlandia durante millones de años.
- El comportamiento de las capas de hielo del pasado fue complejo y variado, especialmente durante los cambios climáticos.
- Las futuras investigaciones con sitios de mayor tasa de deposición podrían refinar la comprensión de la dinámica de la capa de hielo interglacial.
Videos de Conceptos Relacionados
01:50Global Climate Change
29.3K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
29.3K
01:21Green Algae
995
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
995
02:56The Fossil Record
28.1K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
28.1K
01:14The Carbon Cycle
45.3K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
45.3K
01:21Isothermal Processes
5.2K
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
5.2K
01:50Threats to Biodiversity
27.6K
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
27.6K