RESUMEN
Glaciers distinct from the Greenland and Antarctic ice sheets are shrinking rapidly, altering regional hydrology1, raising global sea level2 and elevating natural hazards3. Yet, owing to the scarcity of constrained mass loss observations, glacier evolution during the satellite era is known only partially, as a geographic and temporal patchwork4,5. Here we reveal the accelerated, albeit contrasting, patterns of glacier mass loss during the early twenty-first century. Using largely untapped satellite archives, we chart surface elevation changes at a high spatiotemporal resolution over all of Earth's glaciers. We extensively validate our estimates against independent, high-precision measurements and present a globally complete and consistent estimate of glacier mass change. We show that during 2000-2019, glaciers lost a mass of 267 ± 16 gigatonnes per year, equivalent to 21 ± 3 per cent of the observed sea-level rise6. We identify a mass loss acceleration of 48 ± 16 gigatonnes per year per decade, explaining 6 to 19 per cent of the observed acceleration of sea-level rise. Particularly, thinning rates of glaciers outside ice sheet peripheries doubled over the past two decades. Glaciers currently lose more mass, and at similar or larger acceleration rates, than the Greenland or Antarctic ice sheets taken separately7-9. By uncovering the patterns of mass change in many regions, we find contrasting glacier fluctuations that agree with the decadal variability in precipitation and temperature. These include a North Atlantic anomaly of decelerated mass loss, a strongly accelerated loss from northwestern American glaciers, and the apparent end of the Karakoram anomaly of mass gain10. We anticipate our highly resolved estimates to advance the understanding of drivers that govern the distribution of glacier change, and to extend our capabilities of predicting these changes at all scales. Predictions robustly benchmarked against observations are critically needed to design adaptive policies for the local- and regional-scale management of water resources and cryospheric risks, as well as for the global-scale mitigation of sea-level rise.
RESUMEN
High Mountain Asia hosts the largest glacier concentration outside the polar regions. These glaciers are important contributors to streamflow in one of the most populated areas of the world. Past studies have used methods that can only provide regionally-averaged glacier mass balances to assess the High Mountain Asia glacier contribution to rivers and sea level rise. Here we compute the mass balance for about 92 % of the glacierized area of High Mountain Asia using time series of digital elevation models derived from satellite stereo-imagery. We calculate an average region-wide mass balance of -16.3 ± 3.5 Gt yr-1 (-0.18 ± 0.04 m w.e. yr-1) between 2000 and 2016, which is less negative than most previous estimates. Region-wide mass balances vary from -4.0 ± 1.5 Gt yr-1 (-0.62 ± 0.23 m w.e. yr-1) in Nyainqentanglha to +1.4 ± 0.8 Gt yr-1 (+0.14 ± 0.08 m w.e. yr-1) in Kunlun, with large intra-regional variability of individual glacier mass balances (standard deviation within a region Ë0.20 m w.e. yr-1). Specifically, our results shed light on the Nyainqentanglha and Pamir glacier mass changes, for which contradictory estimates exist in the literature. They provide crucial information for the calibration of the models used for projections of future glacier response to climatic changes, models that presently do not capture the pattern, magnitude and intra-regional variability of glacier changes in High Mountain Asia.
RESUMEN
El síndrome de Guillain-Barré (SGB) es un grupo heterogéneo de alteraciones neurológicas relacionadas que afectan los nervios periféricos del cuerpo. Generalmente se produce después de una infección aguda que favorece a la aparición de una respuesta autoinmune contra las moléculas de los gangliósidos de la mielina de los nervios periféricos. La parálisis facial periférica bilateral es una manifestación neurológica rara (0,3%-2% de los casos) y puede deberse a múltiples etiologías, entre las que se destaca el SGB. Se presenta el caso de un paciente de 39 años que consultó al servicio de urgencias del hospital Universitario del Caribe por parálisis facial bilateral asociada a deterioro motor progresivo y disautonomía. Se realizaron estudios que documentan SGB y se inicia manejo médico con inmunoglobulina intravenosa. El paciente presenta mejoría clínica notoria de su cuadro clínico y es dado de alta del hospital. La parálisis facial periférica bilateral es una entidad neurológica rara que puede asociarse con el síndrome de Guillain-Barré. Es necesario hacer el diagnóstico diferencial respecto de otras entidades clínicas que cursan con parálisis facial periférica bilateral. Se debe iniciar precozmente con inmunoglobulina intravenosa para aumentar la probabilidad de recuperación. El pronóstico es bueno en la mayoría de los casos.
Guillain-Barré syndrome (GBS) is a heterogeneous group of related neurological disorders that affect the peripheral nerves. Generally, it occurs after an acute infection that favors the occurrence of an autoimmune response against the myelin gangliosides molecules of the peripheral nerve. Bilateral peripheral facial nerve paralysis is a rare neurological symptom (0.3%-2% of cases) and may be due to multiple etiologies; among which GBS emerge. The case of a 39 years old patient who consulted by bilateral facial nerve paralysis associated with progressive motor impairment and dysautonomia, is presented. Studies documented GBS. Subsequently, the patient presents successful improvement of his symptoms after intravenous immunoglobulin use and is discharged from the hospital. Bilateral peripheral facial palsy is a rare neurological condition that can be associated with Guillain-Barre syndrome. It is necessary to make the differential diagnosis with other clinical entities presenting with bilateral facial palsy. Intravenous inmunoglbulin should be initiated early to increase the probability of recovery. The prognosis is good in most cases.